/*
* Mini cmp implementation for busybox
*
- *
- * Copyright (C) 2000 by Lineo, inc.
- * Written by Matt Kraai <kraai@alumni.carnegiemellon.edu>
+ * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
*
*/
-#include "busybox.h"
+/* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */
+
+/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
+ *
+ * Original version majorly reworked for SUSv3 compliance, bug fixes, and
+ * size optimizations. Changes include:
+ * 1) Now correctly distinguishes between errors and actual file differences.
+ * 2) Proper handling of '-' args.
+ * 3) Actual error checking of i/o.
+ * 4) Accept SUSv3 -l option. Note that we use the slightly nicer gnu format
+ * in the '-l' case.
+ */
+
#include <stdio.h>
-#include <string.h>
-#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "busybox.h"
+
+static FILE *cmp_xfopen_input(const char *filename)
+{
+ FILE *fp;
+
+ if ((fp = bb_wfopen_input(filename)) != NULL) {
+ return fp;
+ }
+
+ exit(bb_default_error_retval); /* We already output an error message. */
+}
+
+static const char fmt_eof[] = "cmp: EOF on %s\n";
+static const char fmt_differ[] = "%s %s differ: char %d, line %d\n";
+// This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%d %o %o\n"
+static const char fmt_l_opt[] = "%.0s%.0s%d %3o %3o\n";
+
+static const char opt_chars[] = "sl";
+
+enum {
+ OPT_s = 1,
+ OPT_l = 2
+};
int cmp_main(int argc, char **argv)
{
- FILE *fp1 = NULL, *fp2 = stdin;
- char *filename1 = argv[1], *filename2 = "-";
- int c1, c2, char_pos = 1, line_pos = 1;
-
- /* parse argv[] */
- if (argc < 2 || 3 < argc)
- usage(cmp_usage);
-
- fp1 = xfopen(argv[1], "r");
- if (argv[2] != NULL) {
- fp2 = xfopen(argv[2], "r");
- filename2 = argv[2];
+ FILE *fp1, *fp2, *outfile = stdout;
+ const char *filename1, *filename2;
+ const char *fmt;
+ int c1, c2, char_pos, line_pos;
+ int opt_flags;
+ int exit_val = 0;
+
+ bb_default_error_retval = 2; /* 1 is returned if files are different. */
+
+ opt_flags = bb_getopt_ulflags(argc, argv, opt_chars);
+
+ if ((opt_flags == 3) || (((unsigned int)(--argc - optind)) > 1)) {
+ bb_show_usage();
+ }
+
+ fp1 = cmp_xfopen_input(filename1 = *(argv += optind));
+
+ filename2 = "-";
+ if (*++argv) {
+ filename2 = *argv;
+ }
+ fp2 = cmp_xfopen_input(filename2);
+
+ if (fp1 == fp2) { /* Paranioa check... stdin == stdin? */
+ /* Note that we don't bother reading stdin. Neither does gnu wc.
+ * But perhaps we should, so that other apps down the chain don't
+ * get the input. Consider 'echo hello | (cmp - - && cat -)'.
+ */
+ return 0;
}
+ fmt = fmt_differ;
+ if (opt_flags == OPT_l) {
+ fmt = fmt_l_opt;
+ }
+
+ char_pos = 0;
+ line_pos = 1;
do {
- c1 = fgetc(fp1);
- c2 = fgetc(fp2);
- if (c1 != c2) {
- if (c1 == EOF)
- printf("EOF on %s\n", filename1);
- else if (c2 == EOF)
- printf("EOF on %s\n", filename2);
- else
- printf("%s %s differ: char %d, line %d\n", filename1, filename2,
- char_pos, line_pos);
- return EXIT_FAILURE;
+ c1 = getc(fp1);
+ c2 = getc(fp2);
+ ++char_pos;
+ if (c1 != c2) { /* Remember -- a read error may have occurred. */
+ exit_val = 1; /* But assume the files are different for now. */
+ if (c2 == EOF) {
+ /* We know that fp1 isn't at EOF or in an error state. But to
+ * save space below, things are setup to expect an EOF in fp1
+ * if an EOF occurred. So, swap things around.
+ */
+ fp1 = fp2;
+ filename1 = filename2;
+ c1 = c2;
+ }
+ if (c1 == EOF) {
+ bb_xferror(fp1, filename1);
+ fmt = fmt_eof; /* Well, no error, so it must really be EOF. */
+ outfile = stderr;
+ /* There may have been output to stdout (option -l), so
+ * make sure we fflush before writing to stderr. */
+ bb_xfflush_stdout();
+ }
+ if (opt_flags != OPT_s) {
+ if (opt_flags == OPT_l) {
+ line_pos = c1; /* line_pos is unused in the -l case. */
+ }
+ bb_fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
+ if (opt_flags) { /* This must be -l since not -s. */
+ /* If we encountered and EOF, the while check will catch it. */
+ continue;
+ }
+ }
+ break;
+ }
+ if (c1 == '\n') {
+ ++line_pos;
}
- char_pos++;
- if (c1 == '\n')
- line_pos++;
} while (c1 != EOF);
- return EXIT_SUCCESS;
+ bb_xferror(fp1, filename1);
+ bb_xferror(fp2, filename2);
+
+ bb_fflush_stdout_and_exit(exit_val);
}
projects / oweals / busybox.git / blobdiff