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         static int buf_size = -1;
  27         int cnt, c;
  28         char *cp;
  29
  30         /* count single quote characters */
  31         for (cnt = 0, cp = src; *cp; cnt++, cp++)
  32                 if (*cp == '\'')
  33                         cnt += 3;
  34
  35         if (buf_size < cnt) {
  36                 free(buf);
  37                 buf_size = cnt;
  38                 buf = malloc(cnt);
  39         }
  40
  41         cp = buf;
  42         while ((c = *src++)) {
  43                 if (c != '\'')
  44                         *cp++ = c;
  45                 else {
  46                         cp = strcpy(cp, "'\\''");
  47                         cp += 4;
  48                 }
  49         }
  50         *cp = 0;
  51         return buf;
  52 }
  53
  54 static void show_differences(char *name, void *old_contents,
  55                              unsigned long long old_size)
  56 {
  57         FILE *f;
  58         static char *cmd = NULL;
  59         static int cmd_size = -1;
  60
  61         char *name_sq = sq_expand(name);
  62         int cmd_required_length = strlen(name_sq) * 2 + strlen(diff_cmd);
  63
  64         if (cmd_size < cmd_required_length) {
  65                 free(cmd);
  66                 cmd_size = cmd_required_length;
  67                 cmd = malloc(cmd_required_length);
  68         }
  69         snprintf(cmd, cmd_size, diff_cmd, name_sq, name_sq);
  70         f = popen(cmd, "w");
  71         if (old_size)
  72                 fwrite(old_contents, old_size, 1, f);
  73         pclose(f);
  74 }
  75
  76 static void show_diff_empty(struct cache_entry *ce)
  77 {
  78         char *old;
  79         unsigned long int size;
  80         int lines=0;
  81         unsigned char type[20], *p, *end;
  82
  83         old = read_sha1_file(ce->sha1, type, &size);
  84         if (size > 0) {
  85                 int startline = 1;
  86                 int c = 0;
  87
  88                 printf("--- %s\n", ce->name);
  89                 printf("+++ /dev/null\n");
  90                 p = old;
  91                 end = old + size;
  92                 while (p < end)
  93                         if (*p++ == '\n')
  94                                 lines ++;
  95                 printf("@@ -1,%d +0,0 @@\n", lines);
  96                 p = old;
  97                 while (p < end) {
  98                         c = *p++;
  99                         if (startline) {
 100                                 putchar('-');
 101                                 startline = 0;
 102                         }
 103                         putchar(c);
 104                         if (c == '\n')
 105                                 startline = 1;
 106                 }
 107                 if (c!='\n')
 108                         printf("\n");
 109                 fflush(stdout);
 110         }
 111 }
 112
 113 static const char *show_diff_usage = "show-diff [-q] [-s] [-z] [paths...]";
 114
 115 static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
 116 {
 117         int i;
 118         int namelen = ce_namelen(ce);
 119         for (i = 0; i < cnt; i++) {
 120                 int speclen = strlen(spec[i]);
 121                 if (! strncmp(spec[i], ce->name, speclen) &&
 122                     speclen <= namelen &&
 123                     (ce->name[speclen] == 0 ||
 124                      ce->name[speclen] == '/'))
 125                         return 1;
 126         }
 127         return 0;
 128 }
 129
 130 int main(int argc, char **argv)
 131 {
 132         int silent = 0;
 133         int silent_on_nonexisting_files = 0;
 134         int machine_readable = 0;
 135         int entries = read_cache();
 136         int i;
 137
 138         while (1 < argc && argv[1][0] == '-') {
 139                 if (!strcmp(argv[1], "-s"))
 140                         silent_on_nonexisting_files = silent = 1;
 141                 else if (!strcmp(argv[1], "-q"))
 142                         silent_on_nonexisting_files = 1;
 143                 else if (!strcmp(argv[1], "-z"))
 144                         machine_readable = 1;
 145                 else
 146                         usage(show_diff_usage);
 147                 argv++; argc--;
 148         }
 149
 150         /* At this point, if argc == 1, then we are doing everything.
 151          * Otherwise argv[1] .. argv[argc-1] have the explicit paths.
 152          */
 153         if (entries < 0) {
 154                 perror("read_cache");
 155                 exit(1);
 156         }
 157         for (i = 0; i < entries; i++) {
 158                 struct stat st;
 159                 struct cache_entry *ce = active_cache[i];
 160                 int changed;
 161                 unsigned long size;
 162                 char type[20];
 163                 void *old;
 164
 165                 if (1 < argc &&
 166                     ! matches_pathspec(ce, argv+1, argc-1))
 167                         continue;
 168
 169                 if (ce_stage(ce)) {
 170                         if (machine_readable)
 171                                 printf("U %s%c", ce->name, 0);
 172                         else
 173                                 printf("%s: Unmerged\n",
 174                                        ce->name);
 175                         while (i < entries &&
 176                                !strcmp(ce->name, active_cache[i]->name))
 177                                 i++;
 178                         i--; /* compensate for loop control increments */
 179                         continue;
 180                 }
 181
 182                 if (stat(ce->name, &st) < 0) {
 183                         if (errno == ENOENT && silent_on_nonexisting_files)
 184                                 continue;
 185                         if (machine_readable)
 186                                 printf("X %s%c", ce->name, 0);
 187                         else {
 188                                 printf("%s: %s\n", ce->name, strerror(errno));
 189                                 if (errno == ENOENT)
 190                                         show_diff_empty(ce);
 191                         }
 192                         continue;
 193                 }
 194                 changed = cache_match_stat(ce, &st);
 195                 if (!changed)
 196                         continue;
 197                 if (!machine_readable)
 198                         printf("%s: %s\n", ce->name, sha1_to_hex(ce->sha1));
 199                 else {
 200                         printf("%s %s%c", sha1_to_hex(ce->sha1), ce->name, 0);
 201                         continue;
 202                 }
 203                 fflush(stdout);
 204                 if (silent)
 205                         continue;
 206
 207                 old = read_sha1_file(ce->sha1, type, &size);
 208                 show_differences(ce->name, old, size);
 209                 free(old);
 210         }
 211         return 0;
 212 }