ls-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7 #include "blob.h"
   8 #include "tree.h"
   9
  10 static int line_termination = '\n';
  11 #define LS_RECURSIVE 1
  12 #define LS_TREE_ONLY 2
  13 static int ls_options = 0;
  14
  15 static struct tree_entry_list root_entry;
  16
  17 static void prepare_root(unsigned char *sha1)
  18 {
  19         unsigned char rsha[20];
  20         unsigned long size;
  21         void *buf;
  22         struct tree *root_tree;
  23
  24         buf = read_object_with_reference(sha1, "tree", &size, rsha);
  25         free(buf);
  26         if (!buf)
  27                 die("Could not read %s", sha1_to_hex(sha1));
  28
  29         root_tree = lookup_tree(rsha);
  30         if (!root_tree)
  31                 die("Could not read %s", sha1_to_hex(sha1));
  32
  33         /* Prepare a fake entry */
  34         root_entry.directory = 1;
  35         root_entry.executable = root_entry.symlink = 0;
  36         root_entry.mode = S_IFDIR;
  37         root_entry.name = "";
  38         root_entry.item.tree = root_tree;
  39         root_entry.parent = NULL;
  40 }
  41
  42 static int prepare_children(struct tree_entry_list *elem)
  43 {
  44         if (!elem->directory)
  45                 return -1;
  46         if (!elem->item.tree->object.parsed) {
  47                 struct tree_entry_list *e;
  48                 if (parse_tree(elem->item.tree))
  49                         return -1;
  50                 /* Set up the parent link */
  51                 for (e = elem->item.tree->entries; e; e = e->next)
  52                         e->parent = elem;
  53         }
  54         return 0;
  55 }
  56
  57 static struct tree_entry_list *find_entry(const char *path)
  58 {
  59         const char *next, *slash;
  60         int len;
  61         struct tree_entry_list *elem = &root_entry;
  62
  63         /* Find tree element, descending from root, that
  64          * corresponds to the named path, lazily expanding
  65          * the tree if possible.
  66          */
  67
  68         while (path) {
  69                 /* The fact we still have path means that the caller
  70                  * wants us to make sure that elem at this point is a
  71                  * directory, and possibly descend into it.  Even what
  72                  * is left is just trailing slashes, we loop back to
  73                  * here, and this call to prepare_children() will
  74                  * catch elem not being a tree.  Nice.
  75                  */
  76                 if (prepare_children(elem))
  77                         return NULL;
  78
  79                 slash = strchr(path, '/');
  80                 if (!slash) {
  81                         len = strlen(path);
  82                         next = NULL;
  83                 }
  84                 else {
  85                         next = slash + 1;
  86                         len = slash - path;
  87                 }
  88                 if (len) {
  89                         /* (len == 0) if the original path was "drivers/char/"
  90                          * and we have run already two rounds, having elem
  91                          * pointing at the drivers/char directory.
  92                          */
  93                         elem = elem->item.tree->entries;
  94                         while (elem) {
  95                                 if ((strlen(elem->name) == len) &&
  96                                     !strncmp(elem->name, path, len)) {
  97                                         /* found */
  98                                         break;
  99                                 }
 100                                 elem = elem->next;
 101                         }
 102                         if (!elem)
 103                                 return NULL;
 104                 }
 105                 path = next;
 106         }
 107
 108         return elem;
 109 }
 110
 111 static void show_entry_name(struct tree_entry_list *e)
 112 {
 113         /* This is yucky.  The root level is there for
 114          * our convenience but we really want to do a
 115          * forest.
 116          */
 117         if (e->parent && e->parent != &root_entry) {
 118                 show_entry_name(e->parent);
 119                 putchar('/');
 120         }
 121         printf("%s", e->name);
 122 }
 123
 124 static const char *entry_type(struct tree_entry_list *e)
 125 {
 126         return (e->directory ? "tree" : "blob");
 127 }
 128
 129 static const char *entry_hex(struct tree_entry_list *e)
 130 {
 131         return sha1_to_hex(e->directory
 132                            ? e->item.tree->object.sha1
 133                            : e->item.blob->object.sha1);
 134 }
 135
 136 /* forward declaration for mutually recursive routines */
 137 static int show_entry(struct tree_entry_list *, int);
 138
 139 static int show_children(struct tree_entry_list *e, int level)
 140 {
 141         if (prepare_children(e))
 142                 die("internal error: ls-tree show_children called with non tree");
 143         e = e->item.tree->entries;
 144         while (e) {
 145                 show_entry(e, level);
 146                 e = e->next;
 147         }
 148         return 0;
 149 }
 150
 151 static int show_entry(struct tree_entry_list *e, int level)
 152 {
 153         int err = 0;
 154
 155         if (e != &root_entry) {
 156                 printf("%06o %s %s      ", e->mode, entry_type(e),
 157                        entry_hex(e));
 158                 show_entry_name(e);
 159                 putchar(line_termination);
 160         }
 161
 162         if (e->directory) {
 163                 /* If this is a directory, we have the following cases:
 164                  * (1) This is the top-level request (explicit path from the
 165                  *     command line, or "root" if there is no command line).
 166                  *  a. Without any flag.  We show direct children.  We do not
 167                  *     recurse into them.
 168                  *  b. With -r.  We do recurse into children.
 169                  *  c. With -d.  We do not recurse into children.
 170                  * (2) We came here because our caller is either (1-a) or
 171                  *     (1-b).
 172                  *  a. Without any flag.  We do not show our children (which
 173                  *     are grandchildren for the original request).
 174                  *  b. With -r.  We continue to recurse into our children.
 175                  *  c. With -d.  We should not have come here to begin with.
 176                  */
 177                 if (level == 0 && !(ls_options & LS_TREE_ONLY))
 178                         /* case (1)-a and (1)-b */
 179                         err = err | show_children(e, level+1);
 180                 else if (level && ls_options & LS_RECURSIVE)
 181                         /* case (2)-b */
 182                         err = err | show_children(e, level+1);
 183         }
 184         return err;
 185 }
 186
 187 static int list_one(const char *path)
 188 {
 189         int err = 0;
 190         struct tree_entry_list *e = find_entry(path);
 191         if (!e) {
 192                 /* traditionally ls-tree does not complain about
 193                  * missing path.  We may change this later to match
 194                  * what "/bin/ls -a" does, which is to complain.
 195                  */
 196                 return err;
 197         }
 198         err = err | show_entry(e, 0);
 199         return err;
 200 }
 201
 202 static int list(char **path)
 203 {
 204         int i;
 205         int err = 0;
 206         for (i = 0; path[i]; i++)
 207                 err = err | list_one(path[i]);
 208         return err;
 209 }
 210
 211 static const char ls_tree_usage[] =
 212         "git-ls-tree [-d] [-r] [-z] <tree-ish> [path...]";
 213
 214 int main(int argc, char **argv)
 215 {
 216         static char *path0[] = { "", NULL };
 217         char **path;
 218         unsigned char sha1[20];
 219
 220         while (1 < argc && argv[1][0] == '-') {
 221                 switch (argv[1][1]) {
 222                 case 'z':
 223                         line_termination = 0;
 224                         break;
 225                 case 'r':
 226                         ls_options |= LS_RECURSIVE;
 227                         break;
 228                 case 'd':
 229                         ls_options |= LS_TREE_ONLY;
 230                         break;
 231                 default:
 232                         usage(ls_tree_usage);
 233                 }
 234                 argc--; argv++;
 235         }
 236
 237         if (argc < 2)
 238                 usage(ls_tree_usage);
 239         if (get_sha1(argv[1], sha1) < 0)
 240                 usage(ls_tree_usage);
 241
 242         path = (argc == 2) ? path0 : (argv + 2);
 243         prepare_root(sha1);
 244         if (list(path) < 0)
 245                 die("list failed");
 246         return 0;
 247 }