migrate to gitlab

1 files changed, 209 insertions, 0 deletions

diff --git a/magic.c b/magic.c
new file mode 100644
index 0000000..e57e312
--- /dev/null
+++ b/magic.c
@@ -0,0 +1,209 @@
+/*
+ * 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 "file.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <cpio.h>
+#include <search.h>
+#include <sys/types.h>
+#include <tar.h>
+
+enum magic_type {
+	CHAR,
+	UCHAR,
+	SHORT,
+	USHORT,
+	INT,
+	UINT,
+	LONG,
+	ULONG,
+	STRING
+};
+
+size_t sizes[] = {
+	[CHAR] = sizeof(signed char),
+	[UCHAR] = sizeof(unsigned char),
+	[SHORT] = sizeof(short),
+	[USHORT] = sizeof(unsigned short),
+	[INT] = sizeof(int),
+	[UINT] = sizeof(unsigned int),
+	[LONG] = sizeof(long),
+	[ULONG] = sizeof(unsigned long),
+};
+
+union magic_value {
+	signed char schar;
+	unsigned char uchar;
+	short sshort;
+	unsigned short ushort;
+	int sint;
+	unsigned int uint;
+	long slong;
+	unsigned long ulong;
+	char *string;
+};
+
+struct magic {
+	struct magic *next;
+	struct magic *prev;
+	off_t offset;
+	enum magic_type type;
+	union magic_value value;
+	char *message;
+	struct magic *child;
+};
+
+static struct magic *head = NULL;
+static struct magic *tail = NULL;
+static int docontext = 0;
+
+static char *sh_strings[] = { "#!", 0 };
+static char *c_strings[] = { "/*", "#include ", "#define ", 0 };
+static char *fortran_strings[] = { "program ", "PROGRAM ", "c ", "C ", 0 };
+static struct {
+	char *identifier;
+	char **strings;
+} context[] = {
+	{ "commands text", sh_strings },
+	{ "c program text", c_strings },
+	{ "fortran program text", fortran_strings },
+	{ 0, 0 },
+};
+		
+static int addmagic(struct magic *parent, off_t o, enum magic_type t,
+	union magic_value v, char *m)
+{
+	struct magic *magic = calloc(1, sizeof(*magic));
+	if (magic == NULL) {
+		fprintf(stderr, "file: out of memory\n");
+		exit(1);
+	}
+
+	magic->offset = o;
+	magic->type = t;
+	if (t == STRING) {
+		magic->value.string = strdup(v.string);
+	} else {
+		memcpy(&(magic->value), &v, sizeof(v));
+	}
+	magic->message = strdup(m);
+
+	if (parent) {
+	}
+
+	insque(magic, tail);
+	if (tail == NULL) {
+		head = magic;
+		tail = magic;
+	}
+
+	return 0;
+}
+
+static int loadinternal(void)
+{
+	union magic_value cpio;
+	cpio.string = MAGIC;
+	addmagic(NULL, 0, STRING, cpio, "cpio archive");
+
+	union magic_value tar;
+	tar.string = TMAGIC;
+	addmagic(NULL, 0x101, STRING, tar, "tar archive");
+
+	union magic_value ar;
+	ar.string = "!<arch>";
+	addmagic(NULL, 0, STRING, ar, "archive");
+
+	docontext = 1;
+
+	return 0;
+}
+
+int readmagic(const char *path)
+{
+	if (path == NULL) {
+		return loadinternal();
+	}
+
+	return 0;
+}
+
+int idmagic(const char *path)
+{
+	int id = 0;
+
+	FILE *f = fopen(path, "rb");
+	if (f == NULL) {
+		printf(" regular file cannot open (%s)", strerror(errno));
+		return 1;
+	}
+
+	for (struct magic *cursor = head; cursor; cursor = cursor->next) {
+		size_t s = sizes[cursor->type];
+		if (cursor->type == STRING) {
+			s = strlen(cursor->value.string) + 1;
+		}
+		char buf[s];
+
+		if (fseeko(f, cursor->offset, SEEK_SET) != 0) {
+			break;
+		}
+
+		if (fread(buf, s, 1, f) == 0) {
+			break;
+		}
+
+		if (cursor->type == STRING) {
+			buf[s-1] = '\0';
+		}
+
+		if ((cursor->type == STRING && !strcmp(buf, cursor->value.string))
+			|| memcmp(buf, &cursor->value, s) == 0) {
+			printf(" %s", cursor->message);
+			id = 1;
+		}
+	}
+
+	if (docontext) {
+		fseeko(f, 0, SEEK_SET);
+		char *line = NULL;
+		size_t n = 0;
+		getline(&line, &n, f);
+		for (int i = 0; context[i].identifier; i++) {
+			for (int j = 0; context[i].strings[j]; j++) {
+				char *s = context[i].strings[j];
+				if (!strncmp(line, s, strlen(s))) {
+					printf(" %s", context[i].identifier);
+					id = 1;
+				}
+			}
+		}
+	}
+
+	if (id == 0) {
+		printf(" data");
+	}
+
+	fclose(f);
+
+	return 0;
+}