Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * Mini cmp implementation for busybox |
| 4 | * |
Eric Andersen | bdfd0d7 | 2001-10-24 05:00:29 +0000 | [diff] [blame] | 5 | * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu> |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 6 | * |
"Robert P. J. Day" | 801ab14 | 2006-07-12 07:56:04 +0000 | [diff] [blame] | 7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 8 | */ |
| 9 | |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 10 | /* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */ |
| 11 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */ |
| 12 | |
| 13 | /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org) |
| 14 | * |
| 15 | * Original version majorly reworked for SUSv3 compliance, bug fixes, and |
| 16 | * size optimizations. Changes include: |
Eric Andersen | aff114c | 2004-04-14 17:51:38 +0000 | [diff] [blame] | 17 | * 1) Now correctly distinguishes between errors and actual file differences. |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 18 | * 2) Proper handling of '-' args. |
| 19 | * 3) Actual error checking of i/o. |
| 20 | * 4) Accept SUSv3 -l option. Note that we use the slightly nicer gnu format |
| 21 | * in the '-l' case. |
| 22 | */ |
| 23 | |
Eric Andersen | cbe31da | 2001-02-20 06:14:08 +0000 | [diff] [blame] | 24 | #include "busybox.h" |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 25 | |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 26 | static FILE *cmp_xfopen_input(const char * const filename) |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 27 | { |
| 28 | FILE *fp; |
| 29 | |
| 30 | if ((fp = bb_wfopen_input(filename)) != NULL) { |
| 31 | return fp; |
| 32 | } |
| 33 | |
Denis Vlasenko | 4092082 | 2006-10-03 20:28:06 +0000 | [diff] [blame] | 34 | exit(xfunc_error_retval); /* We already output an error message. */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 35 | } |
| 36 | |
| 37 | static const char fmt_eof[] = "cmp: EOF on %s\n"; |
| 38 | static const char fmt_differ[] = "%s %s differ: char %d, line %d\n"; |
Rob Landley | c370ea8 | 2006-03-27 17:00:11 +0000 | [diff] [blame] | 39 | // This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%d %o %o\n" |
| 40 | static const char fmt_l_opt[] = "%.0s%.0s%d %3o %3o\n"; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 41 | |
| 42 | static const char opt_chars[] = "sl"; |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 43 | #define CMP_OPT_s (1<<0) |
| 44 | #define CMP_OPT_l (1<<1) |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 45 | |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 46 | int cmp_main(int argc, char **argv) |
| 47 | { |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 48 | FILE *fp1, *fp2, *outfile = stdout; |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 49 | const char *filename1, *filename2 = "-"; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 50 | const char *fmt; |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 51 | int c1, c2, char_pos = 0, line_pos = 1; |
| 52 | unsigned opt; |
| 53 | int retval = 0; |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 54 | |
Denis Vlasenko | 4092082 | 2006-10-03 20:28:06 +0000 | [diff] [blame] | 55 | xfunc_error_retval = 2; /* 1 is returned if files are different. */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 56 | |
Denis Vlasenko | 67b23e6 | 2006-10-03 21:00:06 +0000 | [diff] [blame] | 57 | opt = getopt32(argc, argv, opt_chars); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 58 | |
Bernhard Reutner-Fischer | a658577 | 2006-09-20 15:29:13 +0000 | [diff] [blame] | 59 | if (((opt & (CMP_OPT_s|CMP_OPT_l)) == (CMP_OPT_s|CMP_OPT_l)) |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 60 | || (((unsigned int)(--argc - optind)) > 1)) |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 61 | bb_show_usage(); |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 62 | |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 63 | fp1 = cmp_xfopen_input(filename1 = *(argv += optind)); |
| 64 | |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 65 | if (*++argv) { |
| 66 | filename2 = *argv; |
| 67 | } |
| 68 | fp2 = cmp_xfopen_input(filename2); |
| 69 | |
| 70 | if (fp1 == fp2) { /* Paranioa check... stdin == stdin? */ |
| 71 | /* Note that we don't bother reading stdin. Neither does gnu wc. |
| 72 | * But perhaps we should, so that other apps down the chain don't |
| 73 | * get the input. Consider 'echo hello | (cmp - - && cat -)'. |
| 74 | */ |
| 75 | return 0; |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 76 | } |
| 77 | |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 78 | if (opt & CMP_OPT_l) |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 79 | fmt = fmt_l_opt; |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 80 | else |
| 81 | fmt = fmt_differ; |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 82 | |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 83 | do { |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 84 | c1 = getc(fp1); |
| 85 | c2 = getc(fp2); |
| 86 | ++char_pos; |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 87 | if (c1 != c2) { /* Remember: a read error may have occurred. */ |
| 88 | retval = 1; /* But assume the files are different for now. */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 89 | if (c2 == EOF) { |
| 90 | /* We know that fp1 isn't at EOF or in an error state. But to |
| 91 | * save space below, things are setup to expect an EOF in fp1 |
| 92 | * if an EOF occurred. So, swap things around. |
| 93 | */ |
| 94 | fp1 = fp2; |
| 95 | filename1 = filename2; |
| 96 | c1 = c2; |
| 97 | } |
| 98 | if (c1 == EOF) { |
Denis Vlasenko | f0ed376 | 2006-10-26 23:21:47 +0000 | [diff] [blame^] | 99 | die_if_ferror(fp1, filename1); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 100 | fmt = fmt_eof; /* Well, no error, so it must really be EOF. */ |
| 101 | outfile = stderr; |
| 102 | /* There may have been output to stdout (option -l), so |
| 103 | * make sure we fflush before writing to stderr. */ |
Rob Landley | d921b2e | 2006-08-03 15:41:12 +0000 | [diff] [blame] | 104 | xfflush_stdout(); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 105 | } |
Bernhard Reutner-Fischer | a658577 | 2006-09-20 15:29:13 +0000 | [diff] [blame] | 106 | if (!(opt & CMP_OPT_s)) { |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 107 | if (opt & CMP_OPT_l) { |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 108 | line_pos = c1; /* line_pos is unused in the -l case. */ |
| 109 | } |
Denis Vlasenko | f0ed376 | 2006-10-26 23:21:47 +0000 | [diff] [blame^] | 110 | fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2); |
Bernhard Reutner-Fischer | 73561cc | 2006-08-28 23:31:54 +0000 | [diff] [blame] | 111 | if (opt) { /* This must be -l since not -s. */ |
| 112 | /* If we encountered an EOF, |
| 113 | * the while check will catch it. */ |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 114 | continue; |
| 115 | } |
| 116 | } |
| 117 | break; |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 118 | } |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 119 | if (c1 == '\n') { |
| 120 | ++line_pos; |
| 121 | } |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 122 | } while (c1 != EOF); |
| 123 | |
Denis Vlasenko | f0ed376 | 2006-10-26 23:21:47 +0000 | [diff] [blame^] | 124 | die_if_ferror(fp1, filename1); |
| 125 | die_if_ferror(fp2, filename2); |
Manuel Novoa III | cad5364 | 2003-03-19 09:13:01 +0000 | [diff] [blame] | 126 | |
Denis Vlasenko | f0ed376 | 2006-10-26 23:21:47 +0000 | [diff] [blame^] | 127 | fflush_stdout_and_exit(retval); |
Mark Whitley | 872138d | 2000-10-09 18:56:47 +0000 | [diff] [blame] | 128 | } |