show-diff.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7
   8 static char *diff_cmd = "diff -L '%s' -u -N  - '%s'";
   9
  10 /* Help to copy the thing properly quoted for the shell safety.
  11  * any single quote is replaced with '\'', and the caller is
  12  * expected to enclose the result within a single quote pair.
  13  *
  14  * E.g.
  15  *  original     sq_expand     result
  16  *  name     ==> name      ==> 'name'
  17  *  a b      ==> a b       ==> 'a b'
  18  *  a'b      ==> a'\''b    ==> 'a'\''b'
  19  *
  20  * NOTE! The returned memory belongs to this function so
  21  * do not free it.
  22  */
  23 static char *sq_expand(char *src)
  24 {
  25         static char *buf = NULL;
  26         int cnt, c;
  27         char *cp;
  28
  29         /* count bytes needed to store the quoted string. */
  30         for (cnt = 1, cp = src; *cp; cnt++, cp++)
  31                 if (*cp == '\'')
  32                         cnt += 3;
  33
  34         if (! (buf = malloc(cnt)))
  35             return buf;
  36         cp = buf;
  37         while ((c = *src++)) {
  38                 if (c != '\'')
  39                         *cp++ = c;
  40                 else {
  41                         cp = strcpy(cp, "'\\''");
  42                         cp += 4;
  43                 }
  44         }
  45         *cp = 0;
  46         return buf;
  47 }
  48
  49 static void show_differences(char *name, void *old_contents,
  50                              unsigned long long old_size)
  51 {
  52         FILE *f;
  53         char *name_sq = sq_expand(name);
  54         int cmd_size = strlen(name_sq) * 2 + strlen(diff_cmd);
  55         char *cmd = malloc(cmd_size);
  56
  57         snprintf(cmd, cmd_size, diff_cmd, name_sq, name_sq);
  58         f = popen(cmd, "w");
  59         if (old_size)
  60                 fwrite(old_contents, old_size, 1, f);
  61         pclose(f);
  62         free(name_sq);
  63         free(cmd);
  64 }
  65
  66 static void show_diff_empty(struct cache_entry *ce)
  67 {
  68         char *old;
  69         unsigned long int size;
  70         int lines=0;
  71         unsigned char type[20], *p, *end;
  72
  73         old = read_sha1_file(ce->sha1, type, &size);
  74         if (! old) {
  75                 error("unable to read blob object for %s (%s)", ce->name,
  76                       sha1_to_hex(ce->sha1));
  77                 return;
  78         }
  79         if (size > 0) {
  80                 int startline = 1;
  81                 int c = 0;
  82
  83                 printf("--- %s\n", ce->name);
  84                 printf("+++ /dev/null\n");
  85                 p = old;
  86                 end = old + size;
  87                 while (p < end)
  88                         if (*p++ == '\n')
  89                                 lines ++;
  90                 printf("@@ -1,%d +0,0 @@\n", lines);
  91                 p = old;
  92                 while (p < end) {
  93                         c = *p++;
  94                         if (startline) {
  95                                 putchar('-');
  96                                 startline = 0;
  97                         }
  98                         putchar(c);
  99                         if (c == '\n')
 100                                 startline = 1;
 101                 }
 102                 if (c!='\n')
 103                         printf("\n");
 104                 fflush(stdout);
 105         }
 106 }
 107
 108 static const char *show_diff_usage = "show-diff [-q] [-s] [-z] [paths...]";
 109
 110 static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
 111 {
 112         int i;
 113         int namelen = ce_namelen(ce);
 114         for (i = 0; i < cnt; i++) {
 115                 int speclen = strlen(spec[i]);
 116                 if (! strncmp(spec[i], ce->name, speclen) &&
 117                     speclen <= namelen &&
 118                     (ce->name[speclen] == 0 ||
 119                      ce->name[speclen] == '/'))
 120                         return 1;
 121         }
 122         return 0;
 123 }
 124
 125 int main(int argc, char **argv)
 126 {
 127         int silent = 0;
 128         int silent_on_nonexisting_files = 0;
 129         int machine_readable = 0;
 130         int entries = read_cache();
 131         int i;
 132
 133         while (1 < argc && argv[1][0] == '-') {
 134                 if (!strcmp(argv[1], "-s"))
 135                         silent_on_nonexisting_files = silent = 1;
 136                 else if (!strcmp(argv[1], "-q"))
 137                         silent_on_nonexisting_files = 1;
 138                 else if (!strcmp(argv[1], "-z"))
 139                         machine_readable = 1;
 140                 else
 141                         usage(show_diff_usage);
 142                 argv++; argc--;
 143         }
 144
 145         /* At this point, if argc == 1, then we are doing everything.
 146          * Otherwise argv[1] .. argv[argc-1] have the explicit paths.
 147          */
 148         if (entries < 0) {
 149                 perror("read_cache");
 150                 exit(1);
 151         }
 152         for (i = 0; i < entries; i++) {
 153                 struct stat st;
 154                 struct cache_entry *ce = active_cache[i];
 155                 int changed;
 156                 unsigned long size;
 157                 char type[20];
 158                 void *old;
 159
 160                 if (1 < argc &&
 161                     ! matches_pathspec(ce, argv+1, argc-1))
 162                         continue;
 163
 164                 if (ce_stage(ce)) {
 165                         if (machine_readable)
 166                                 printf("U %s%c", ce->name, 0);
 167                         else
 168                                 printf("%s: Unmerged\n",
 169                                        ce->name);
 170                         while (i < entries &&
 171                                !strcmp(ce->name, active_cache[i]->name))
 172                                 i++;
 173                         i--; /* compensate for loop control increments */
 174                         continue;
 175                 }
 176
 177                 if (stat(ce->name, &st) < 0) {
 178                         if (errno == ENOENT && silent_on_nonexisting_files)
 179                                 continue;
 180                         if (machine_readable)
 181                                 printf("X %s%c", ce->name, 0);
 182                         else {
 183                                 printf("%s: %s\n", ce->name, strerror(errno));
 184                                 if (errno == ENOENT)
 185                                         show_diff_empty(ce);
 186                         }
 187                         continue;
 188                 }
 189                 changed = cache_match_stat(ce, &st);
 190                 if (!changed)
 191                         continue;
 192                 if (!machine_readable)
 193                         printf("%s: %s\n", ce->name, sha1_to_hex(ce->sha1));
 194                 else {
 195                         printf("%s %s%c", sha1_to_hex(ce->sha1), ce->name, 0);
 196                         continue;
 197                 }
 198                 fflush(stdout);
 199                 if (silent)
 200                         continue;
 201
 202                 old = read_sha1_file(ce->sha1, type, &size);
 203                 if (! old)
 204                         error("unable to read blob object for %s (%s)",
 205                               ce->name, sha1_to_hex(ce->sha1));
 206                 else
 207                         show_differences(ce->name, old, size);
 208                 free(old);
 209         }
 210         return 0;
 211 }