migrate to gitlab

1 files changed, 178 insertions, 0 deletions

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;
+}