migrate to gitlab

39 files changed, 2535 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..8e9252e
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,43 @@
+.POSIX:
+
+.SUFFIXES: .cat .msg
+
+default: all
+
+CFLAGS=-g -Wall -Wextra -Wpedantic -Werror -Wno-unused-function
+
+UTILITY=sh
+SOURCES=alias.c bg.c builtins.c cd.c command.c false.c fc.c fg.c getopts.c \
+	hash.c jobs.c kill.c newgrp.c pwd.c read.c set.c main.c true.c type.c \
+	ulimit.c umask.c wait.c \
+	dot.c eval.c exec.c exit.c export.c readonly.c shift.c times.c trap.c \
+	unset.c \
+	interactive.c parse.c init.c
+HEADERS=sh.h
+OBJECTS=alias.o bg.o builtins.o cd.o command.o false.o fc.o fg.o getopts.o \
+	hash.o jobs.o kill.o newgrp.o pwd.o read.o set.o main.o true.o type.o \
+	ulimit.o umask.o wait.o \
+	dot.o eval.o exec.o exit.o export.o readonly.o shift.o times.o trap.o \
+	unset.o \
+	interactive.o parse.o init.o \
+	sh.tab.o sh.yy.o
+BUILTINS=alias bg cd command false fc fg getopts jobs kill newgrp pwd read \
+	true ulimit umask unalias wait
+
+all: $(UTILITY) $(L10N) $(BUILTINS)
+
+sh: $(OBJECTS) $(HEADERS)
+	$(CC) -o $@ $(CFLAGS) $(OBJECTS) -ly -ll
+
+$(BUILTINS): $(UTILITY)
+	#ln -s $(UTILITY) $@
+	for i in $(BUILTINS); do ln -s sh $$i; done
+
+sh.yy.c: sh.l sh.tab.h
+	$(LEX) -t sh.l > $@
+
+sh.tab.h sh.tab.c: sh.y
+	$(YACC) -b sh -tvd sh.y
+
+clean:
+	rm -f *.o $(L10N) $(UTILITY) $(BUILTINS) sh.tab.[ch] sh.yy.c
diff --git a/alias.c b/alias.c
new file mode 100644
index 0000000..23c557a
--- /dev/null
+++ b/alias.c
@@ -0,0 +1,94 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct alias {
+	char *alias;
+	char *command;
+};
+
+static struct alias *aliases = NULL;
+
+static void set_alias(const char *alias, const char *command)
+{
+	(void)alias; (void)command;
+}
+
+char * sh_get_alias(const char *alias)
+{
+	if (aliases == NULL) {
+		return NULL;
+	}
+
+	for (int i = 0; aliases[i].alias; i++) {
+		if (!strcmp(aliases[i].alias, alias)) {
+			return aliases[i].command;
+		}
+	}
+
+	return NULL;
+}
+
+static void show_alias(const char *alias)
+{
+	char *command = sh_get_alias(alias);
+	if (command) {
+		printf("%s=%s\n", alias, command);
+	} else {
+		fprintf(stderr, "alias: %s: not found\n", alias);
+	}
+}
+
+int alias_main(int argc, char *argv[])
+{
+	while (getopt(argc, argv, "") != -1) {
+		return 1;
+	}
+
+	if (argv[optind] == NULL) {
+		for (int i = 0; aliases && aliases[i].alias; i++) {
+			printf("%s=%s\n", aliases[i].alias, aliases[i].command);
+		}
+		return 0;
+	}
+
+	do {
+		char *a = argv[optind++];
+		char *eq = strchr(a, '=');
+		if (eq) {
+			*eq = '\0';
+			set_alias(a, eq + 1);
+		} else {
+			show_alias(a);
+		}
+	} while (optind < argc);
+
+	return 0;
+}
+
+int unalias_main(int argc, char **argv)
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/bg.c b/bg.c
new file mode 100644
index 0000000..e700864
--- /dev/null
+++ b/bg.c
@@ -0,0 +1,8 @@
+#define _XOPEN_SOURCE 700
+#include <stdio.h>
+
+int bg_main(int argc, char *argv[])
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/builtins.c b/builtins.c
new file mode 100644
index 0000000..886ebaf
--- /dev/null
+++ b/builtins.c
@@ -0,0 +1,167 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stddef.h>
+#include <string.h>
+#include <libgen.h>
+#include <unistd.h>
+
+struct builtin {
+        const char *name;
+        int (*main)(int argc, char *argv[]);
+};
+
+/* Special built-ins */
+/* break */
+/* : */
+/* continue */
+int dot_main(int argc, char *argv[]);
+int eval_main(int argc, char *argv[]);
+int exec_main(int argc, char *argv[]);
+int exit_main(int argc, char *argv[]);
+int export_main(int argc, char *argv[]);
+int readonly_main(int argc, char *argv[]);
+/* return */
+int set_main(int argc, char *argv[]);
+int shift_main(int argc, char *argv[]);
+int times_main(int argc, char *argv[]);
+int trap_main(int argc, char *argv[]);
+int unset_main(int argc, char *argv[]);
+
+static struct builtin special_builtins[] = {
+	{ "break", NULL },
+	{ ":", NULL },
+	{ "continue", NULL },
+	{ ".", dot_main },
+	{ "eval", eval_main },
+	{ "exec", exec_main },
+	{ "exit", exit_main },
+	{ "export", export_main },
+	{ "readonly", readonly_main },
+	{ "return", NULL },
+	{ "set", set_main },
+	{ "shift", shift_main },
+	{ "times", times_main },
+	{ "trap", trap_main },
+	{ "unset", unset_main },
+	{ 0, 0 },
+};
+
+/* Regular built-ins */
+int alias_main(int argc, char *argv[]);
+int bg_main(int argc, char *argv[]);
+int cd_main(int argc, char *argv[]);
+int command_main(int argc, char *argv[]);
+int false_main(int argc, char *argv[]);
+int fc_main(int argc, char *argv[]);
+int fg_main(int argc, char *argv[]);
+int getopts_main(int argc, char *argv[]);
+int jobs_main(int argc, char *argv[]);
+int kill_main(int argc, char *argv[]);
+int newgrp_main(int argc, char *argv[]);
+int pwd_main(int argc, char *argv[]);
+int read_main(int argc, char *argv[]);
+int true_main(int argc, char *argv[]);
+int ulimit_main(int argc, char *argv[]);
+int umask_main(int argc, char *argv[]);
+int unalias_main(int argc, char *argv[]);
+int wait_main(int argc, char *argv[]);
+
+static struct builtin regular_builtins[] = {
+	{ "alias", alias_main },
+	{ "bg", bg_main },
+	{ "cd", cd_main },
+	{ "command", command_main },
+	{ "false", false_main },
+	{ "fc", fc_main },
+	{ "fg", fg_main },
+	{ "getopts", getopts_main },
+	{ "jobs", jobs_main },
+	{ "kill", kill_main },
+	{ "newgrp", newgrp_main },
+	{ "pwd", pwd_main },
+	{ "read", read_main },
+	{ "true", true_main },
+	{ "ulimit", ulimit_main },
+	{ "umask", umask_main },
+	{ "unalias", unalias_main },
+	{ "wait", wait_main },
+	{ 0, 0 },
+};
+
+static int (*sh_getbuiltin(const char *util, struct builtin *bi))(int argc, char *argv[])
+{
+	for (int i = 0; bi[i].name; i++) {
+		if (!strcmp(bi[i].name, util)) {
+			return bi[i].main;
+		}
+	}
+
+	return NULL;
+}
+
+int sh_builtin(int argc, char *argv[])
+{
+	char *util = basename(argv[0]);
+	if (!strcmp(util, "break")) {
+		return BREAK;
+	} else if (!strcmp(util, ":")) {
+		return 0;
+	} else if (!strcmp(util, "continue")) {
+		return CONTINUE;
+	} else if (!strcmp(util, "return")) {
+		return RETURN;
+	}
+
+	int (*m)(int, char *[]) = sh_getbuiltin(util, special_builtins);
+	if (m == NULL) {
+		m = sh_getbuiltin(util, regular_builtins);
+		if (m == NULL) {
+			return 1;
+		}
+	}
+
+	optind = 1;
+	opterr = 1;
+	optarg = NULL;
+
+	return m(argc, argv);
+}
+
+static int is_builtin(const char *util, struct builtin *bi)
+{
+	for (int i = 0; bi[i].name; i++) {
+		if (!strcmp(bi[i].name, util)) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+int sh_is_special_builtin(const char *util)
+{
+	return is_builtin(util, special_builtins);
+}
+
+int sh_is_regular_builtin(const char *util)
+{
+	return is_builtin(util, regular_builtins);
+}
diff --git a/cd.c b/cd.c
new file mode 100644
index 0000000..a914c19
--- /dev/null
+++ b/cd.c
@@ -0,0 +1,122 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+
+#define FLAG_L (1)
+#define FLAG_P (2)
+
+static int cd(char *path, int flag)
+{
+	int alloced = 0;
+	int print = 0;
+
+	if (path == NULL) {
+		path = getenv("HOME");
+		if (path == NULL || !strcmp(path, "")) {
+			fprintf(stderr, "cd: Directory not specified and HOME not found\n");
+			return 1;
+		}
+	}
+
+	if (!strcmp(path, "-")) {
+		path = getenv("OLDPWD");
+		print = 1;
+	}
+
+	/*
+	if (!(path[0] == '/' || !strncmp(path, "./", 2) || !strncmp(path, "../", 3))) {
+		char *opath = path;
+		path = sh_find_in_path(opath, "CDPATH");
+		if (path == NULL) {
+			fprintf(stderr, "cd: %s not found in CDPATH\n", opath);
+			return 1;
+		}
+		alloced = 1;
+	}
+	*/
+
+	if (flag != FLAG_P) {
+		if (path[0] != '/') {
+			char *base = getenv("PWD");
+			char newpath[strlen(base) + strlen(path)];
+			sprintf(newpath, "%s/%s", base, path);
+			strcpy(path, newpath);
+		}
+
+		/* TODO: canonicalize path */
+		/* TODO: shorten to <= PATH_MAX */
+	}
+
+	char *oldpwd = getenv("PWD");
+	if (chdir(path) != 0) {
+		if (alloced) {
+			free(path);
+		}
+
+		fprintf(stderr, "cd: Couldn't change to %s: %s\n", path, strerror(errno));
+		return 1;
+	}
+
+	if (alloced) {
+		free(path);
+	}
+
+	if (print) {
+		puts(path);
+	}
+
+	setenv("OLDPWD", oldpwd, 1);
+	setenv("PWD", path, 1);
+	return 0;
+}
+
+int cd_main(int argc, char *argv[])
+{
+	int flag = 0;
+	int c;
+
+	while ((c = getopt(argc, argv, ":LP")) != -1) {
+		switch (c) {
+		case 'L':
+			flag = FLAG_L;
+			break;
+
+		case 'P':
+			flag = FLAG_P;
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (optind < argc - 1) {
+		fprintf(stderr, "cd: too many arguments\n");
+		return 1;
+	}
+
+	return cd(argv[optind], flag);
+}
diff --git a/command.c b/command.c
new file mode 100644
index 0000000..0307927
--- /dev/null
+++ b/command.c
@@ -0,0 +1,72 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#define _XOPEN_SOURCE 700
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static int show(const char *cmd, const char *path, bool showtype)
+{
+	(void)cmd; (void)path; (void)showtype;
+	return 0;
+}
+
+int command_main(int argc, char *argv[])
+{
+	char *path = getenv("PATH");
+	char defaultpath[PATH_MAX];
+	bool showcommand = false;
+	bool showtype = false;
+
+	int c = 0;
+	while ((c = getopt(argc, argv, "pvV")) != -1) {
+		switch(c) {
+		case 'p':
+			confstr(_CS_PATH, defaultpath, sizeof(defaultpath));
+			path = defaultpath;
+			break;
+
+		case 'V':
+			showtype = true;
+			/* fallthru */
+		case 'v':
+			showcommand = true;
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (showcommand && optind != argc - 1) {
+		fprintf(stderr, "command: Options -v and -V require command and no arguments\n");
+		return 1;
+	}
+
+	if (showcommand) {
+		return show(argv[optind], path, showtype);
+	}
+
+	/* Run command */
+
+	return 0;
+}
diff --git a/dot.c b/dot.c
new file mode 100644
index 0000000..36f5e59
--- /dev/null
+++ b/dot.c
@@ -0,0 +1,28 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <unistd.h>
+
+int dot_main(int argc, char *argv[])
+{
+	printf("%s: not implemented\n", argv[0]);
+	return argc;
+}
diff --git a/eval.c b/eval.c
new file mode 100644
index 0000000..1a3d895
--- /dev/null
+++ b/eval.c
@@ -0,0 +1,39 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct sh_redirect *sh_add_redirect(int fd, int direction, char *name)
+{
+	struct sh_redirect *red = malloc(sizeof(*red));
+	red->fd = fd;
+	red->direction = direction;
+	red->name = strdup(name);
+	return red;
+}
+
+int eval_main(int argc, char *argv[])
+{
+	printf("%s: not implemented\n", argv[0]);
+	return argc;
+}
diff --git a/exec.c b/exec.c
new file mode 100644
index 0000000..1ebf63c
--- /dev/null
+++ b/exec.c
@@ -0,0 +1,48 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+int exec_main(int argc, char *argv[])
+{
+	while (getopt(argc, argv, "") != -1) {
+		return 1;
+	}
+
+	if (argv[optind] == NULL) {
+		/* keep redirects for this shell */
+		return 0;
+	}
+
+	char *path = sh_find_in_path(argv[optind], "PATH");
+	if (path == NULL) {
+		fprintf(stderr, "exec: %s: %s\n", argv[optind], strerror(ENOENT));
+		exit(127);
+	}
+
+	execve(path, argv + optind, exported_environ);
+	fprintf(stderr, "exec: %s: %s\n", argv[optind], strerror(errno));
+	exit(126);
+	return 126;
+}
diff --git a/exit.c b/exit.c
new file mode 100644
index 0000000..0b827f9
--- /dev/null
+++ b/exit.c
@@ -0,0 +1,52 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int exit_main(int argc, char *argv[])
+{
+	static int exiting = 0;
+
+	while (getopt(argc, argv, "") != -1) {
+		return 1;
+	}
+
+	if (optind < argc - 1) {
+		fprintf(stderr, "exit: only one exit status supported\n");
+		return 1;
+	}
+
+	int r = 0;
+
+	if (argv[optind]) {
+		r = atoi(argv[optind]);
+	}
+
+	if (exiting == 0) {
+		exiting = 1;
+		sh_trap(0);
+	}
+
+	exit(r);
+	_exit(r);
+	return r;
+}
diff --git a/export.c b/export.c
new file mode 100644
index 0000000..214a3d4
--- /dev/null
+++ b/export.c
@@ -0,0 +1,100 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+char **exported_environ = NULL;
+static int nexports = 0;
+
+void sh_export(const char *env)
+{
+	char *value = getenv(env);
+	if (value == NULL) {
+		return;
+	}
+	size_t klen = strlen(env);
+
+	char *keyval = calloc(klen + strlen(value) + 2, 1);
+	sprintf(keyval, "%s=%s", env, value);
+
+	for (int i = 0; i < nexports; i++) {
+		if (!strncmp(exported_environ[i], env, klen)
+			&& exported_environ[i][klen] == '=') {
+			free(exported_environ[i]);
+			exported_environ[i] = keyval;
+			return;
+		}
+	}
+
+	nexports++;
+	exported_environ = realloc(exported_environ,
+		nexports * sizeof(*exported_environ));
+	exported_environ[nexports-1] = keyval;
+}
+
+int export_main(int argc, char *argv[])
+{
+	int print = 0;
+
+	int c;
+	while ((c = getopt(argc, argv, "p")) != EOF) {
+		switch (c) {
+		case 'p':	/** print exported variables **/
+			print = 1;
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (print && argv[optind] != NULL) {
+		fprintf(stderr, "export: can't display and export at the same time\n");
+		return 1;
+	}
+
+	if (print) {
+		for (char **e = exported_environ; e && *e; e++) {
+			char *env = strdup(*e);
+			size_t len = strlen(env);
+			if (env[len - 1] == '=') {
+				env[len - 1] = '\0';
+			}
+			printf("export %s\n", env);
+			free(env);
+		}
+		return 0;
+	}
+
+	do {
+		char *var = argv[optind++];
+		char *eq = strchr(var, '=');
+		if (eq) {
+			putenv(var);
+			*eq = '\0';
+		}
+		sh_export(var);
+	} while (optind < argc);
+
+	return 0;
+}
diff --git a/false.c b/false.c
new file mode 100644
index 0000000..0997f7d
--- /dev/null
+++ b/false.c
@@ -0,0 +1,24 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+int false_main(int argc, char *argv[])
+{
+	(void)argc; (void)argv;
+	return 1;
+}
diff --git a/fc.c b/fc.c
new file mode 100644
index 0000000..3eb3b55
--- /dev/null
+++ b/fc.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+fc_main(int argc, char **argv)
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/fg.c b/fg.c
new file mode 100644
index 0000000..0240ee7
--- /dev/null
+++ b/fg.c
@@ -0,0 +1,8 @@
+#define _XOPEN_SOURCE 700
+#include <stdio.h>
+
+int fg_main(int argc, char *argv[])
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/getopts.c b/getopts.c
new file mode 100644
index 0000000..263b1a2
--- /dev/null
+++ b/getopts.c
@@ -0,0 +1,8 @@
+#define _XOPEN_SOURCE 700
+#include <stdio.h>
+
+int getopts_main(int argc, char *argv[])
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/hash.c b/hash.c
new file mode 100644
index 0000000..1f08dd8
--- /dev/null
+++ b/hash.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+hash_main(int argc, char **argv)
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/init.c b/init.c
new file mode 100644
index 0000000..fa6c229
--- /dev/null
+++ b/init.c
@@ -0,0 +1,51 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+extern char **environ;
+
+void sh_init(int interactive)
+{
+	if (interactive && getuid() == geteuid() && getgid() == getegid()) {
+		char *env = getenv("ENV");
+		if (env) {
+		/*
+			char *profile = sh_expand(env);
+			sh_source(env);
+			free(profile);
+		*/
+		}
+	}
+
+	/* export all inherited environment variables */
+	char **exp = environ;
+	while (exp && *exp) {
+		char *e = strdup(*exp);
+		char *eq = strchr(e, '=');
+		*eq = '\0';
+		sh_export(e);
+		free(e);
+		exp++;
+	}
+}
diff --git a/interactive.c b/interactive.c
new file mode 100644
index 0000000..7460327
--- /dev/null
+++ b/interactive.c
@@ -0,0 +1,58 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+static char *sh_getline(char **cmdline)
+{
+	char *prompt = getenv(*cmdline ? "PS2" : "PS1");
+	/* wordexpand prompt */
+	fprintf(stderr, "%s", prompt);
+
+	size_t n = 0;
+	getline(cmdline, &n, stdin);
+	return *cmdline;
+}
+
+int sh_interactive(void)
+{
+	while (!feof(stdin)) {
+		char *cmdline = NULL;
+		sh_getline(&cmdline);
+
+		if (cmdline == NULL) {
+			break;
+		}
+
+		struct command *command = sh_parse(cmdline);
+		while (command == NULL) {
+			/* append more text */
+			/* attempt parsing again */
+		}
+
+		sh_execute(command);
+
+		free(cmdline);
+		sh_freecmd(command);
+	}
+
+	return 0;
+}
diff --git a/jobs.c b/jobs.c
new file mode 100644
index 0000000..5fe1c6e
--- /dev/null
+++ b/jobs.c
@@ -0,0 +1,8 @@
+#define _XOPEN_SOURCE 700
+#include <stdio.h>
+
+int jobs_main(int argc, char *argv[])
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/kill.c b/kill.c
new file mode 100644
index 0000000..31cc706
--- /dev/null
+++ b/kill.c
@@ -0,0 +1,101 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+
+struct {
+	char *name;
+	int num;
+} ksigs[] = {
+	{ "ABRT",	SIGABRT },
+	{ "ALRM",	SIGALRM },
+	{ "BUS",	SIGBUS },
+	{ "CHLD",	SIGCHLD },
+	{ "CONT",	SIGCONT },
+	{ "FPE",	SIGFPE },
+	{ "HUP",	SIGHUP },
+	{ "ILL",	SIGILL },
+	{ "INT",	SIGINT },
+	{ "KILL",	SIGKILL },
+	{ "PIPE",	SIGPIPE },
+	{ "QUIT",	SIGQUIT },
+	{ "SEGV",	SIGSEGV },
+	{ "STOP",	SIGSTOP },
+	{ "TERM",	SIGTERM },
+	{ "TSTP",	SIGTSTP },
+	{ "TTIN",	SIGTTIN },
+	{ "TTOU",	SIGTTOU },
+	{ "USR1",	SIGUSR1 },
+	{ "USR2",	SIGUSR2 },
+	{ "POLL",	SIGPOLL },
+	{ "PROF",	SIGPROF },
+	{ "SYS",	SIGSYS },
+	{ "TRAP",	SIGTRAP },
+	{ "URG",	SIGURG },
+	{ "VTALRM",	SIGVTALRM },
+	{ "XCPU",	SIGXCPU },
+	{ "XFSZ",	SIGXFSZ },
+};
+size_t nsigs = sizeof(ksigs) / sizeof(ksigs[0]);
+
+int kill_main(int argc, char *argv[])
+{
+	char *signame = "TERM";
+	int list = 0;
+
+	opterr = 0;
+	int c;
+	while ((c = getopt(argc, argv, "s:l") != -1)) {
+		switch (c) {
+		case 's':	/** send signal [signal_name] **/
+			signame = optarg;
+			break;
+
+		case 'l':
+			list = 1;
+			break;
+
+		default:
+			if (isdigit(optopt) || isupper(optopt)) {
+				signame = argv[optind];
+				break;
+			}
+			fprintf(stderr, "kill: unknown option '-%c'\n", optopt);
+			//return 1;
+		}
+	}
+
+	if (list) {
+		if (argv[optind]) {
+		}
+
+		for (size_t i = 0; i < nsigs; i++) {
+			printf("%s%c", ksigs[i].name, i < nsigs - 1 ? ' ' : '\n');
+		}
+		return 0;
+	}
+
+	printf("%s\n", signame);
+
+	return 0;
+}
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..61b55f3
--- /dev/null
+++ b/main.c
@@ -0,0 +1,105 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <libgen.h>
+#include <unistd.h>
+
+int sh_main(int argc, char *argv[])
+{
+	enum { STDIN, INTERACTIVE, COMMAND } mode = STDIN;
+	int c;
+	while ((c = getopt(argc, argv, "abCefhimnuvxo:cs")) != -1) {
+		switch (c) {
+		case 'a':	/** export all variables **/
+		case 'b':	/** notify of background job completions **/
+		case 'C':	/** don't clobber existing files with > **/
+		case 'e':	/** exit on failure **/
+		case 'f':	/** disable pathname expansion **/
+		case 'h':	/** hash utilities in functions when defined **/
+		case 'n':	/** read commands but don't execute **/
+		case 'u':	/** don't expand unset parameters **/
+		case 'v':	/** echo input to /stderr/ **/
+		case 'x':	/** enable tracing **/
+			sh_set(c, 1);
+			break;
+
+		case 'o':	/** enable [option] **/
+			sh_seto(optarg, 1);
+			break;
+
+		case 'c':	/** execute [command_string] and return **/
+			mode = COMMAND;
+			break;
+
+		case 'i':	/** run an interactive shell **/
+			mode = INTERACTIVE;
+			break;
+
+		case 's':	/** read commands from /stdin/ **/
+			mode = STDIN;
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	while (argv[optind] && argv[optind][0] == '+') {
+		/* consume these */
+		optind++;
+	}
+
+	if (mode == COMMAND) {
+		/* shift argv */
+		execvp(argv[optind], argv + optind);
+		fprintf(stderr, "sh: %s: %s\n", argv[optind], strerror(errno));
+		return 1;
+	}
+
+	if (argv[optind] == NULL && isatty(STDIN_FILENO) && isatty(STDERR_FILENO)) {
+		mode = INTERACTIVE;
+	}
+
+	sh_init(mode == INTERACTIVE);
+
+	/* set $1-$# */
+
+	if (mode == INTERACTIVE) {
+		return sh_interactive();
+	}
+
+	/* mode is STDIN */
+	return yyparse();
+}
+
+int main(int argc, char *argv[])
+{
+	putenv("PS1=$ ");
+	char *base = basename(argv[0]);
+	if (sh_is_regular_builtin(base)) {
+		return sh_builtin(argc, argv);
+	}
+	
+	return sh_main(argc, argv);
+}
diff --git a/newgrp.c b/newgrp.c
new file mode 100644
index 0000000..3148df1
--- /dev/null
+++ b/newgrp.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+int newgrp_main(int argc, char **argv)
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/parse.c b/parse.c
new file mode 100644
index 0000000..91ce97f
--- /dev/null
+++ b/parse.c
@@ -0,0 +1,178 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+struct simple_command {
+	int argc;
+	char **argv;
+	char **redirection;
+};
+
+struct pipeline_command {
+	struct simple_command s;
+};
+
+struct list_command {
+	struct simple_command s;
+};
+
+struct compound_command {
+	enum { GROUPING, FOR, CASE, IF, UNTIL } type;
+	struct simple_command *commands;
+};
+
+struct command {
+	enum { EMPTY, SIMPLE, PIPELINE, LIST, COMPOUND } type;
+	union {
+		struct simple_command simple;
+		struct pipeline_command pipeline;
+		struct list_command list;
+		struct compound_command compound;
+	} cmd;
+};
+
+struct command *sh_parse(const char *cmdline)
+{
+	char *l = strdup(cmdline);
+	char *start = l;
+	while (isspace(*start)) {
+		start++;
+	}
+
+	char *end = l + strlen(l) - 1;
+	while (isspace(*end) && end > start) {
+		*end = '\0';
+		end--;
+	}
+
+	struct command *cmd = calloc(1, sizeof(*cmd));
+	if (cmd == NULL) {
+		/* TODO: should probably crash here */
+		return cmd;
+	}
+
+	cmd->type = SIMPLE;
+	cmd->cmd.simple.argv = calloc(100, sizeof(char *));
+
+	char *next = strtok(start, " ");
+	do {
+		cmd->cmd.simple.argv[cmd->cmd.simple.argc++] = strdup(next);
+	} while ((next = strtok(NULL, " ")) != NULL);
+	
+	free(l);
+	return cmd;
+}
+
+void sh_freecmd(struct command *command)
+{
+	if (command->type == SIMPLE) {
+		struct simple_command *c = &(command->cmd.simple);
+		for (int i = 0; c->argv[i]; i++) {
+			free(c->argv[i]);
+		}
+	}
+	free(command);
+}
+
+char *sh_find_in_path(const char *file, const char *pathvar)
+{
+	char *path = getenv(pathvar);
+	if (path == NULL) {
+		return NULL;
+	}
+
+	path = strdup(path);
+	char *checkpath = strtok(path, ":");
+	do {
+		char fullpath[strlen(checkpath) + strlen(file) + 2];
+		sprintf(fullpath, "%s/%s", checkpath, file);
+		if (access(fullpath, F_OK) == 0) {
+			free(path);
+			return strdup(fullpath);
+		}
+	} while ((checkpath = strtok(NULL, ":")) != NULL);
+
+	free(path);
+	return NULL;
+}
+
+int sh_simple_command(struct simple_command *c)
+{
+	char *path = c->argv[0];
+
+	if (!strchr(path, '/')) {
+		if (sh_is_special_builtin(path)) {
+			return sh_builtin(c->argc, c->argv);
+		}
+
+		/*
+		if (sh_is_function(path)) {
+			return sh_function(c->argc, c->argv);
+		}
+		*/
+
+		if (sh_is_regular_builtin(path)) {
+			return sh_builtin(c->argc, c->argv);
+		}
+
+		path = sh_find_in_path(path, "PATH");
+	}
+
+	if (path == NULL) {
+		fprintf(stderr, "sh: %s: %s\n", c->argv[0], strerror(ENOENT));
+	}
+
+	pid_t pid = fork();
+	if (pid == 0) {
+		execv(path, c->argv/*, exported_environ*/);
+		fprintf(stderr, "sh: %s: %s\n", path, strerror(errno));
+		exit(1);
+	} 
+	free(path);
+
+	if (pid < 0) {
+		perror("sh");
+		return 1;
+	}
+
+	int rv;
+	waitpid(pid, &rv, 0);
+	return rv;
+}
+
+int sh_execute(struct command *command)
+{
+	if (command->type == EMPTY) {
+		return 0;
+	}
+
+	if (command->type == SIMPLE) {
+		return sh_simple_command(&(command->cmd.simple));
+	}
+
+	return 0;
+}
diff --git a/pwd.c b/pwd.c
new file mode 100644
index 0000000..00e26e2
--- /dev/null
+++ b/pwd.c
@@ -0,0 +1,64 @@
+/*
+ * UNG's Not GNU
+ * 
+ * Copyright (c) 2011, Jakob Kaivo <jakob@kaivo.net>
+ * 
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+const char *pwd_desc = "return working directory name";
+const char *pwd_inv  = "pwd [-L|-P]";
+
+int
+pwd_main (int argc, char **argv)
+{
+  //char mode = 'L';
+  char *cwd;
+  int c;
+
+  while ((c = getopt (argc, argv, ":LP")) != -1) {
+    switch (c) {
+      case 'L':
+      case 'P':
+        ////mode = c;
+        break;
+      default:
+        return 1;
+    }
+  }
+
+  if (optind < argc)
+    return 1;
+ 
+  // FIXME:
+  // if (mode == 'L')
+  //   if (cwd !~ /./ && cwd !~ /../)
+  //     print (cwd);
+  //   else if (strlen (cwd) > PATH_MAX && NO_DOT_OR_DOT_DOT)
+  //     unspecified
+  //   else
+  //     mode = 'P';
+  // if (mode == 'P')
+  //  decompose_to_shortest_path
+  //  print (decomposed)
+  cwd = (char*)getenv ("PWD");
+  printf ("%s\n", cwd);
+
+  return 0;
+}
diff --git a/read.c b/read.c
new file mode 100644
index 0000000..c60255f
--- /dev/null
+++ b/read.c
@@ -0,0 +1,68 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int read_main(int argc, char *argv[])
+{
+	int escapes = 1;
+
+	int c;
+	while ((c = getopt(argc, argv, "r")) != -1) {
+		switch (c) {
+		case 'r':	/** do not interpet \ escapes **/
+			escapes = 0;
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (argv[optind] == NULL) {
+		fprintf(stderr, "read: at least one variable required\n");
+		return 1;
+	}
+
+	while (argv[optind]) {
+		char *line = NULL;
+		size_t n = 0;
+
+		getline(&line, &n, stdin);
+
+		/* strip trailing newline */
+		if (escapes) {
+		}
+
+		setenv(argv[optind], line, 1);
+
+		if (sh_get('a')) {
+			sh_export(argv[optind]);
+		}
+
+		free(line);
+
+		optind++;
+	}
+
+	return 0;
+}
diff --git a/readonly.c b/readonly.c
new file mode 100644
index 0000000..93809cc
--- /dev/null
+++ b/readonly.c
@@ -0,0 +1,28 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <unistd.h>
+
+int readonly_main(int argc, char *argv[])
+{
+	printf("%s: not implemented\n", argv[0]);
+	return argc;
+}
diff --git a/set.c b/set.c
new file mode 100644
index 0000000..de7f288
--- /dev/null
+++ b/set.c
@@ -0,0 +1,135 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+static struct option {
+	char c;
+	char *s;
+	int value;
+} sh_options[] = {
+	{ 'a', "allexport", 0 },
+	{ 'b', NULL, 0 },
+	{ 'C', "noclobber", 0 },
+	{ 'e', "errexit", 0 },
+	{ 'f', "noglob", 0 },
+	{ 'h', NULL, 0 },
+	{ 'm', "monitor", 0 },
+	{ 'n', NULL, 0 },
+	{ 'u', "nounset", 0 },
+	{ 'v', "verbose", 0 },
+	{ 'x', "xtrace", 0 },
+	{ '-', "ignoreeof", 0 },
+	{ '-', "nolog", 0 },
+	{ '-', "vi", 0 },
+};
+static size_t noptions = sizeof(sh_options) / sizeof(sh_options[0]);
+
+void sh_set(char option, int value)
+{
+	for (size_t i = 0; i < noptions; i++) {
+		if (sh_options[i].c == option) {
+			sh_options[i].value = value;
+			return;
+		}
+	}
+}
+
+int sh_get(char option)
+{
+	for (size_t i = 0; i < noptions; i++) {
+		if (sh_options[i].c == option) {
+			return sh_options[i].value;
+		}
+	}
+	return 0;
+}
+
+void sh_seto(char *option, int value)
+{
+	for (size_t i = 0; i < noptions; i++) {
+		if (sh_options[i].s && !strcmp(sh_options[i].s, option)) {
+			sh_options[i].value = value;
+			return;
+		}
+	}
+}
+
+int sh_geto(char *option)
+{
+	for (size_t i = 0; i < noptions; i++) {
+		if (sh_options[i].s && !strcmp(sh_options[i].s, option)) {
+			return sh_options[i].value;
+		}
+	}
+	return 0;
+}
+
+int set_main(int argc, char *argv[])
+{
+	int show = 0;
+
+	int c;
+	while ((c = getopt(argc, argv, ":abCefhmnuvxo:")) != -1) {
+		switch (c) {
+		case 'a':
+		case 'b':
+		case 'C':
+		case 'e':
+		case 'f':
+		case 'h':
+		case 'm':
+		case 'n':
+		case 'u':
+		case 'v':
+		case 'x':
+			sh_set(c, 1);
+			break;
+
+		case 'o':
+			sh_seto(optarg, 1);
+			break;
+
+		case ':':
+			if (optopt == 'o') {
+				show = 1;
+			} else {
+				return 1;
+			}
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (show) {
+		for (size_t i = 0; i < noptions; i++) {
+			if (sh_options[i].value) {
+				putchar(sh_options[i].c);
+			}
+		}
+		putchar('\n');
+	}
+
+	return 0;
+}
diff --git a/sh.h b/sh.h
new file mode 100644
index 0000000..ba43bac
--- /dev/null
+++ b/sh.h
@@ -0,0 +1,68 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#define _XOPEN_SOURCE 700
+#define _POSIX_C_SOURCE 200809L
+
+struct sh_redirect {
+	int fd;
+	enum { WRITE, APPEND, OVERWRITE, WRITEFD, READWRITE, READ, READFD, READHERE, READDASH } direction;
+	char *name;
+};
+
+struct sh_redirect *sh_add_redirect(int fd, int direction, char *name);
+
+struct sh_command {
+	int argc;
+	char *cmd;
+	char **argv;
+	struct sh_redirect *redirect;
+};
+
+struct command;
+struct command *sh_parse(const char *cmdline);
+void sh_freecmd(struct command *cmd);
+int sh_execute(struct command *cmd);
+
+void sh_set(char option, int value);
+void sh_seto(char *option, int value);
+int sh_get(char option);
+int sh_geto(char *option);
+
+int sh_interactive(void);
+
+int sh_is_special_builtin(const char *util);
+int sh_is_regular_builtin(const char *util);
+int (*sh_get_builtin(const char *util))(int argc, char *argv[]);
+int sh_builtin(int argc, char *argv[]);
+
+enum { BREAK = -1, CONTINUE = -2, RETURN = -3 };
+
+char *sh_find_in_path(const char *file, const char *pathvar);
+
+void sh_export(const char *var);
+extern char **exported_environ;
+
+void sh_init(int interactive);
+
+enum { HUP = 1, INT = 2, QUIT = 3, ABRT = 6, KILL = 9, ALRM = 14, TERM = 15 };
+
+void sh_trap(int trapno);
+
+int yyparse(void);
diff --git a/sh.l b/sh.l
new file mode 100644
index 0000000..539a251
--- /dev/null
+++ b/sh.l
@@ -0,0 +1,65 @@
+%{
+#include "sh.h"
+#include "sh.tab.h"
+/* thanks, flex, for implicitly declaring identifiers */
+/* bonus points for something that isn't part of ISO C */
+extern int fileno(FILE *);
+%}
+
+NAME [_a-zA-Z0-9]
+NONDIGIT [_a-zA-Z]
+DIGIT [0-9]
+WHITESPACE [ \t]
+OPERATOR [()|;&<>]
+
+%s FOR
+%x COMMENT
+
+%%
+
+"#"		{ BEGIN COMMENT; }
+<COMMENT>.	;
+<COMMENT>\n	{ BEGIN INITIAL; }
+
+"&&"/.	{ return AND_IF; }
+"||"/.	{ return OR_IF; }
+";;"/.	{ return DSEMI; }
+"<<"/.	{ return DLESS; }
+">>"/.	{ return DGREAT; }
+"<&"/.	{ return LESSAND; }
+">&"/.	{ return GREATAND; }
+"<>"/.	{ return LESSGREAT; }
+"<<-"/.	{ return DLESSDASH; }
+">|"/.	{ return CLOBBER; }
+
+"if"	{ return If; }
+"then"	{ return Then; }
+"else"	{ return Else; }
+"elif"	{ return Elif; }
+"fi"	{ return Fi; }
+"do"	{ return Do; }
+"done"	{ BEGIN INITIAL; return Done; }
+"case"	{ return Case; }
+"esac"	{ return Esac; }
+"while"	{ return While; }
+"until"	{ return Until; }
+"for"	{ BEGIN FOR; return For; }
+
+"{"	{ return Lbrace; }
+"}"	{ return Rbrace; }
+"!"	{ return Bang; }
+
+"in"	{ return In; }
+
+{OPERATOR}/.	{ return yytext[0]; }
+
+{DIGIT}+/<	{ yylval.n = atoi(yytext); return IO_NUMBER; }
+{DIGIT}+/>	{ yylval.n = atoi(yytext); return IO_NUMBER; }
+
+\n		{ return NEWLINE; }
+
+<FOR>{NONDIGIT}{NAME}*	{ yylval.s = yytext; return NAME; }
+
+[^ \t\n()|;&<>]+	{ yylval.s = yytext; return WORD; }
+
+{WHITESPACE}	;
diff --git a/sh.y b/sh.y
new file mode 100644
index 0000000..14ad022
--- /dev/null
+++ b/sh.y
@@ -0,0 +1,312 @@
+%{
+#include "sh.h"
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Thanks, Bison, for implicitly declaring identifiers */
+extern int yylex(void);
+extern int yyerror(const char *);
+extern char *yytext;
+%}
+
+%union {
+	int n;
+	char *s;
+	struct sh_command *cmd;
+	struct sh_redirect *redir;
+}
+
+%token<s> WORD ASSIGNMENT_WORD NAME
+%token NEWLINE
+%token<n> IO_NUMBER
+%token AND_IF OR_IF DSEMI
+%token DLESS DGREAT LESSAND GREATAND LESSGREAT DLESSDASH
+%token CLOBBER
+%token If Then Else Elif Fi Do Done
+%token Case Esac While Until For
+%token Lbrace Rbrace Bang
+%token In
+
+ /* %type<cmd> simple_command */
+%type<s> filename here_end cmd_name cmd_word
+%type<redir> io_redirect io_file io_here
+
+%start complete_command
+%%
+complete_command : list separator
+	| list
+	;
+
+list	: list separator_op and_or
+	| and_or
+	;
+
+and_or	: pipeline
+	| and_or AND_IF linebreak pipeline
+	| and_or OR_IF linebreak pipeline
+	;
+
+pipeline : pipe_sequence
+	| Bang pipe_sequence
+	;
+
+pipe_sequence : command
+	| pipe_sequence '|' linebreak command
+	;
+
+command	: simple_command 
+	| compound_command
+	| compound_command redirect_list
+	| function_definition
+	;
+
+compound_command : brace_group
+	| subshell
+	| for_clause
+	| case_clause
+	| if_clause
+	| while_clause
+	| until_clause
+	;
+
+subshell : '(' compound_list ')'
+	;
+
+compound_list : term
+	| newline_list term
+	| term separator
+	| newline_list term separator
+	;
+
+term	: term separator and_or
+	| and_or
+	;
+
+for_clause : For name linebreak do_group
+	| For name linebreak in sequential_sep do_group
+	| For name linebreak in wordlist sequential_sep do_group
+	;
+
+name	: NAME { /* apply rule 5 */
+		printf("NAME: %s\n", yytext);
+	}
+	;
+
+in	: In	/* apply rule 6 */
+	;
+
+wordlist : wordlist WORD
+	| WORD {
+		printf("WORD: %s\n", yytext);
+	}
+	;
+
+case_clause : Case WORD linebreak in linebreak case_list Esac
+	| Case WORD linebreak in linebreak case_list_ns Esac
+	| Case WORD linebreak in linebreak Esac
+	;
+
+case_list_ns : case_list case_item_ns
+	| case_item_ns
+	;
+
+case_list : case_list case_item
+	| case_item
+	;
+
+case_item_ns : pattern ')' linebreak
+	| pattern ')' compound_list linebreak
+	| '(' pattern ')' linebreak
+	| '(' pattern ')' compound_list linebreak
+	;
+
+case_item : pattern ')' linebreak DSEMI linebreak
+	| pattern ')' compound_list DSEMI linebreak
+	| '(' pattern ')' linebreak DSEMI linebreak
+	| '(' pattern ')' compound_list DSEMI linebreak
+	;
+
+pattern	: WORD	/* apply rule 4 */
+	| pattern '|' WORD	/* do *NOT* apply rule 4 */
+	;
+
+if_clause : If compound_list Then compound_list else_part Fi
+	| If compound_list Then compound_list Fi
+	;
+
+else_part : Elif compound_list Then compound_list
+	| Elif compound_list Then compound_list else_part
+	| Else compound_list
+	;
+
+while_clause : While compound_list do_group
+	;
+
+until_clause : Until compound_list do_group
+	;
+
+function_definition : fname '(' ')' linebreak function_body
+
+function_body : compound_command	/* apply rule 9 */
+	| compound_command redirect_list /* apply rule 9 */
+	;
+
+fname	: NAME				/* apply rule 8 */
+	;
+
+brace_group : Lbrace compound_list Rbrace
+	;
+
+do_group : Do compound_list Done	/* apply rule 6 */
+	;
+
+simple_command : cmd_prefix cmd_word cmd_suffix
+	| cmd_prefix cmd_word {
+		printf("simple_command:cmd_prefix '%s'\n", $2);
+	}
+	| cmd_prefix
+	| cmd_name cmd_suffix {
+		printf("simple_command:'%s' cmd_suffix\n", $1);
+	}
+	| cmd_name {
+		printf("simple_command:'%s'\n", $1);
+	}
+	;
+
+cmd_name : WORD {
+		/* rule 7a */
+		$$ = strdup($1);
+	}
+	;
+
+cmd_word : WORD {
+		/* rule 7b */
+		$$ = strdup($1);
+	}
+	;
+
+cmd_prefix : io_redirect
+	| cmd_prefix io_redirect
+	| ASSIGNMENT_WORD
+	| cmd_prefix ASSIGNMENT_WORD
+	;
+
+cmd_suffix : io_redirect
+	| cmd_suffix io_redirect
+	| WORD {
+		printf("cmd_suffix:WORD:%s\n", $1);
+	}
+	| cmd_suffix WORD {
+		printf("cmd_suffix:cmd_suffix WORD:%s\n", $2);
+	}
+	;
+
+redirect_list : io_redirect {
+		printf("Redirect fd %d, dir %d, name %s\n", $1->fd, $1->direction, $1->name);
+	}
+	| redirect_list io_redirect {
+		printf("Redirect fd %d, dir %d, name %s\n", $2->fd, $2->direction, $2->name);
+	}
+	;
+
+io_redirect : io_file {
+		$$ = $1;
+		printf("Redirect fd %d to %s\n", $1->fd, $1->name);
+	}
+	| IO_NUMBER io_file {
+		$2->fd = $1;
+		printf("Redirect fd %d to %s\n", $2->fd, $2->name);
+		$$ = $2;
+	}
+	| io_here {
+		printf("Redirect fd %d until %s\n", $1->fd, $1->name);
+		$$ = $1;
+	}
+	| IO_NUMBER io_here {
+		$2->fd = $1;
+		printf("Redirect fd %d until %s\n", $2->fd, $2->name);
+		$$ = $2;
+	}
+	;
+
+io_file : '<' filename {
+		$$ = sh_add_redirect(STDIN_FILENO, READ, $2);
+	}
+	| LESSAND filename {
+		$$ = sh_add_redirect(STDIN_FILENO, READFD, $2);
+	}
+	| '>' filename {
+		$$ = sh_add_redirect(STDOUT_FILENO, WRITE, $2);
+	}
+	| GREATAND filename {
+		$$ = sh_add_redirect(STDOUT_FILENO, WRITEFD, $2);
+	}
+	| DGREAT filename {
+		$$ = sh_add_redirect(STDOUT_FILENO, APPEND, $2);
+	}
+	| LESSGREAT filename {
+		$$ = sh_add_redirect(-1, READWRITE, $2);
+	}
+	| CLOBBER filename {
+		$$ = sh_add_redirect(STDOUT_FILENO, OVERWRITE, $2);
+	}
+	;
+
+filename : WORD {
+		/* rule 2 */
+		$$ = yytext;
+	}
+	;
+
+io_here	: DLESS here_end {
+		$$ = sh_add_redirect(STDIN_FILENO, READHERE, $2);
+	}
+	| DLESSDASH here_end {
+		$$ = sh_add_redirect(STDIN_FILENO, READDASH, $2);
+	}
+	;
+
+here_end : WORD {
+		/* rule 3 */
+		$$ = yytext;
+	}
+	;
+
+newline_list : NEWLINE {
+		puts("newline_list:NEWLINE");
+	}
+	| newline_list NEWLINE {
+		puts("newline_list:newline_list:NEWLINE");
+	}
+	;
+
+linebreak : newline_list {
+		puts("linebreak:newline_list");
+	}
+	| /* empty */
+	;
+
+separator_op : '&' {
+		puts("separator_op:&");
+	}
+	| ';' {
+		puts("separator_op:;");
+	}
+	;
+
+separator : separator_op linebreak {
+		puts("separator: separator_op linebreak");
+	}
+	| newline_list {
+		puts("separator:newline_list");
+	}
+	;
+
+sequential_sep : ';' linebreak {
+		puts("sequential_sep:; linebreak");
+	}
+	| newline_list {
+		puts("sequential_sep:newline_list");
+	}
+	;
diff --git a/shift.c b/shift.c
new file mode 100644
index 0000000..01ff3c7
--- /dev/null
+++ b/shift.c
@@ -0,0 +1,28 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <unistd.h>
+
+int shift_main(int argc, char *argv[])
+{
+	printf("%s: not implemented\n", argv[0]);
+	return argc;
+}
diff --git a/times.c b/times.c
new file mode 100644
index 0000000..d70c153
--- /dev/null
+++ b/times.c
@@ -0,0 +1,51 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <time.h>
+#include <sys/times.h>
+#include <unistd.h>
+
+#define clocktos(c) ((double)(c) / (double)CLOCKS_PER_SEC)
+#define clocktom(c) ((long)clocktos(c) / 60)
+#define clocktof(c) ((double)(clocktos(c)) - (double)(clocktom(c) * 60))
+
+/* The Standard specifies an exit status of "Zero." with no other options. */
+
+int times_main(int argc, char *argv[])
+{
+	while (getopt(argc, argv, "") != -1) {
+		/* produce warning only */
+	}
+
+	if (argv[optind]) {
+		fprintf(stderr, "times: no arguments supported\n");
+		/* keep going */
+	}
+
+	struct tms tms;
+	times(&tms);
+	printf("%ldm%fs %ldm%fs\n%ldm%fs %ldm%fs\n",
+		clocktom(tms.tms_utime), clocktof(tms.tms_utime),
+		clocktom(tms.tms_stime), clocktof(tms.tms_stime),
+		clocktom(tms.tms_cutime), clocktof(tms.tms_cutime),
+		clocktom(tms.tms_cstime), clocktof(tms.tms_cstime));
+	return 0;
+}
diff --git a/trap.c b/trap.c
new file mode 100644
index 0000000..20cb65b
--- /dev/null
+++ b/trap.c
@@ -0,0 +1,183 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <unistd.h>
+
+static struct {
+	char *name;
+	char *value;
+} traps[] = {
+	[0] =		{ "EXIT", 0 },
+	[SIGABRT] =	{ "ABRT", 0 },
+	[SIGALRM] =	{ "ALRM", 0 },
+	[SIGBUS] =	{ "BUS", 0 },
+	[SIGCHLD] =	{ "CHLD", 0 },
+	[SIGCONT] =	{ "CONT", 0 },
+	[SIGFPE] =	{ "FPE", 0 },
+	[SIGHUP] =	{ "HUP", 0 },
+	[SIGILL] =	{ "ILL", 0 },
+	[SIGINT] =	{ "INT", 0 },
+	[SIGKILL] =	{ "KILL", 0 },
+	[SIGPIPE] =	{ "PIPE", 0 },
+	[SIGQUIT] =	{ "QUIT", 0 },
+	[SIGSEGV] =	{ "SEGV", 0 },
+	[SIGSTOP] =	{ "STOP", 0 },
+	[SIGTERM] =	{ "TERM", 0 },
+	[SIGTSTP] =	{ "TSTP", 0 },
+	[SIGTTIN] =	{ "TTIN", 0 },
+	[SIGTTOU] =	{ "TTOU", 0 },
+	[SIGUSR1] =	{ "USR1", 0 },
+	[SIGUSR2] =	{ "USR2", 0 },
+	[SIGPOLL] =	{ "POLL", 0 },
+	[SIGPROF] =	{ "PROF", 0 },
+	[SIGSYS] =	{ "SYS", 0 },
+	[SIGTRAP] =	{ "TRAP", 0 },
+	[SIGURG] =	{ "URG", 0 },
+	[SIGVTALRM] =	{ "VTALRM", 0 },
+	[SIGXCPU] =	{ "XCPU", 0 },
+	[SIGXFSZ] =	{ "XFSZ", 0 },
+};
+static size_t ntraps = sizeof(traps) / sizeof(traps[0]);
+
+static char *tnums[] = {
+	[0] = "EXIT",
+	[HUP] = "HUP",
+	[INT] = "INT",
+	[QUIT] = "QUIT",
+	[ABRT] = "ABRT",
+	[KILL] = "KILL",
+	[ALRM] = "ALRM",
+	[TERM] = "TERM",
+};
+static size_t nnums = sizeof(tnums) / sizeof(tnums[0]);
+
+static int trap_num(const char *name)
+{
+	if (!strcmp(name, "0")) {
+		return 0;
+	}
+
+	int t = atoi(name);
+	if (t != 0) {
+		if ((size_t)t < nnums && tnums[t] != NULL) {
+			name = tnums[t];
+		}
+	}
+
+	for (size_t i = 0; i < ntraps; i++) {
+		if (traps[i].name && !strcmp(traps[i].name, name)) {
+			return i;
+		}
+	}
+	fprintf(stderr, "trap: unknown trap '%s'\n", name);
+	return -1;
+}
+
+static int trap_reset(const char *trap)
+{
+	int t = trap_num(trap);
+	if (t == -1) {
+		return 1;
+	}
+
+	free(traps[t].value);
+	traps[t].value = NULL;
+	signal(t, SIG_DFL);
+	return 0;
+}
+
+void sh_trap(int trapno)
+{
+	if (traps[trapno].value) {
+		/* sh_eval(traps[trapno].value); */
+	}
+}
+
+static int trap_set(const char *trap, const char *action)
+{
+	int t = trap_num(trap);
+	if (t == -1) {
+		return 1;
+	}
+
+	if (t == SIGKILL || t == SIGSTOP) {
+		fprintf(stderr, "trap: setting trap for %s is undefined\n", trap);
+		return 1;
+	}
+
+	if (traps[t].value) {
+		free(traps[t].value);
+	}
+	traps[t].value = strdup(action);
+
+	if (!strcmp(action, "")) {
+		signal(t, SIG_IGN);
+	} else {
+		signal(t, sh_trap);
+	}
+
+	return 0;
+}
+
+int trap_main(int argc, char *argv[])
+{
+	while (getopt(argc, argv, "") != -1) {
+		return 1;
+	}
+
+	if (argv[optind] == NULL) {
+		for (size_t i = 0; i < ntraps; i++) {
+			if (traps[i].value) {
+				printf("trap -- %s %s\n", traps[i].value, traps[i].name);
+			}
+		}
+		return 0;
+	}
+
+	char *action = argv[optind];
+	int r = 0;
+
+	/* FIXME */
+	if (atoi(action) > 0) {
+		do {
+			r |= trap_reset(argv[optind++]);
+		} while (argv[optind]);
+		return r;
+	}
+
+	optind++;
+
+	if (!strcmp(action, "-")) {
+		do {
+			r |= trap_reset(argv[optind++]);
+		} while (argv[optind]);
+		return r;
+	}
+
+	do {
+		r |= trap_set(argv[optind++], action);
+	} while (argv[optind]);
+
+	return r;
+}
diff --git a/true.c b/true.c
new file mode 100644
index 0000000..c3c9e8c
--- /dev/null
+++ b/true.c
@@ -0,0 +1,24 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+int true_main(int argc, char *argv[])
+{
+	(void)argc; (void)argv;
+	return 0;
+}
diff --git a/type.c b/type.c
new file mode 100644
index 0000000..b3f0bf5
--- /dev/null
+++ b/type.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+int type_main(int argc, char **argv)
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}
diff --git a/ulimit.c b/ulimit.c
new file mode 100644
index 0000000..3367a61
--- /dev/null
+++ b/ulimit.c
@@ -0,0 +1,61 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/resource.h>
+#include <unistd.h>
+
+#define BLOCKSIZE (512)
+
+int ulimit_main(int argc, char *argv[])
+{
+	int c;
+	while ((c = getopt(argc, argv, "f")) != -1) {
+		switch (c) {
+		case 'f':	/** set or report limit in blocks **/
+			/* is default */
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (argv[optind]) {
+		struct rlimit rl;
+		rl.rlim_cur = atoi(argv[optind]) * BLOCKSIZE;
+		if (setrlimit(RLIMIT_FSIZE, &rl) == -1) {
+			perror("ulimit");
+			return 1;
+		}
+		return 0;
+	}
+
+	struct rlimit rl;
+	getrlimit(RLIMIT_FSIZE, &rl);
+	if (rl.rlim_cur == RLIM_INFINITY) {
+		printf("unlimited\n");
+	} else {
+		printf("%ld\n", rl.rlim_cur / BLOCKSIZE);
+	}
+
+	return 0;
+}
diff --git a/umask.c b/umask.c
new file mode 100644
index 0000000..f6fca22
--- /dev/null
+++ b/umask.c
@@ -0,0 +1,68 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+int umask_main(int argc, char *argv[])
+{
+	int symbolic = 0;
+
+	int c;
+	while ((c = getopt(argc, argv, "S")) != -1) {
+		switch (c) {
+		case 'S':	/** produce symbolic output **/
+			symbolic = 1;
+			break;
+
+		default:
+			return 1;
+		}
+	}
+
+	if (argv[optind]) {
+		fprintf(stderr, "umask: TODO\n");
+		return 1;
+	}
+
+	mode_t mask = umask(0);
+	umask(mask);
+
+	if (symbolic) {
+		fputs("u=", stdout);
+		fputs(mask & S_IRUSR ? "" : "r", stdout);
+		fputs(mask & S_IWUSR ? "" : "w", stdout);
+		fputs(mask & S_IXUSR ? "" : "x", stdout);
+		fputs(",g=", stdout);
+		fputs(mask & S_IRGRP ? "" : "r", stdout);
+		fputs(mask & S_IWGRP ? "" : "w", stdout);
+		fputs(mask & S_IXGRP ? "" : "x", stdout);
+		fputs(",o=", stdout);
+		fputs(mask & S_IRGRP ? "" : "r", stdout);
+		fputs(mask & S_IWGRP ? "" : "w", stdout);
+		fputs(mask & S_IXGRP ? "" : "x", stdout);
+		putchar('\n');
+	} else {
+		printf("%04o\n", mask);
+	}
+
+	return 0;
+}
diff --git a/unset.c b/unset.c
new file mode 100644
index 0000000..62be7be
--- /dev/null
+++ b/unset.c
@@ -0,0 +1,28 @@
+/*
+ * UNG's Not GNU
+ *
+ * Copyright (c) 2011-2017, Jakob Kaivo <jkk@ung.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "sh.h"
+#include <stdio.h>
+#include <unistd.h>
+
+int unset_main(int argc, char *argv[])
+{
+	printf("%s: not implemented\n", argv[0]);
+	return argc;
+}
diff --git a/wait.c b/wait.c
new file mode 100644
index 0000000..16b64d7
--- /dev/null
+++ b/wait.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+wait_main(int argc, char **argv)
+{
+	printf("Sorry, %s isn't implemented yet.\n", argv[0]);
+	return argc;
+}