diff options
Diffstat (limited to 'coreutils/cmp.c')
| -rw-r--r-- | coreutils/cmp.c | 156 |
1 files changed, 115 insertions, 41 deletions
diff --git a/coreutils/cmp.c b/coreutils/cmp.c index 07bf3be..43dbc84 100644 --- a/coreutils/cmp.c +++ b/coreutils/cmp.c @@ -20,59 +20,133 @@ * */ +/* 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 distingusishes 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 <getopt.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"; +#if 0 +static const char fmt_l_opt[] = "%.0s%.0s%d %o %o\n"; /* SUSv3 format */ +#else +static const char fmt_l_opt[] = "%.0s%.0s%d %3o %3o\n"; /* nicer gnu format */ +#endif + +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, *filename2 = "-"; - int c, c1, c2, char_pos = 1, line_pos = 1, silent = FALSE; - - while ((c = getopt(argc, argv, "s")) != EOF) { - switch (c) { - case 's': - silent = TRUE; - break; - default: - show_usage(); - } + 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(); } - filename1 = argv[optind]; - switch (argc - optind) { - case 2: - fp2 = xfopen(filename2 = argv[optind + 1], "r"); - case 1: - fp1 = xfopen(filename1, "r"); - break; - default: - 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 (silent) - return EXIT_FAILURE; - 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); } |