update-index: --stdin and -z

The new option --stdin reads list of paths to be updated from the
standard input.  As usual, -z means the paths are terminated with NUL
characters, as opposed to LF without that option.

This is useful to use git-diff-files -z and git-ls-files -z when the
platform xargs does not support -0 option, and obviously saves one
process even when xargs can take -0.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/update-index.c b/update-index.c
index 1ea36ea..01eaa1a 100644 (file)
--- a/update-index.c
+++ b/update-index.c
@@ -4,6 +4,7 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "cache.h"
+#include "strbuf.h"
 
 /*
  * Default to not allowing changes to the list of files. The
@@ -277,11 +278,30 @@ static int add_cacheinfo(const char *arg1, const char *arg2, const char *arg3)
 
 static struct cache_file cache_file;
 
+
+static void update_one(const char *path, const char *prefix, int prefix_length)
+{
+       const char *p = prefix_path(prefix, prefix_length, path);
+       if (!verify_path(p)) {
+               fprintf(stderr, "Ignoring path %s\n", path);
+               return;
+       }
+       if (force_remove) {
+               if (remove_file_from_cache(p))
+                       die("git-update-index: unable to remove %s", path);
+               return;
+       }
+       if (add_file_to_cache(p))
+               die("Unable to process file %s", path);
+}
+
 int main(int argc, const char **argv)
 {
-       int i, newfd, entries, has_errors = 0;
+       int i, newfd, entries, has_errors = 0, line_termination = '\n';
        int allow_options = 1;
+       int read_from_stdin = 0;
        const char *prefix = setup_git_directory();
+       int prefix_length = prefix ? strlen(prefix) : 0;
 
        newfd = hold_index_file_for_update(&cache_file, get_index_file());
        if (newfd < 0)
@@ -335,25 +355,33 @@ int main(int argc, const char **argv)
                                force_remove = 1;
                                continue;
                        }
-
+                       if (!strcmp(path, "-z")) {
+                               line_termination = 0;
+                               continue;
+                       }
+                       if (!strcmp(path, "--stdin")) {
+                               if (i != argc - 1)
+                                       die("--stdin must be at the end");
+                               read_from_stdin = 1;
+                               break;
+                       }
                        if (!strcmp(path, "--ignore-missing")) {
                                not_new = 1;
                                continue;
                        }
                        die("unknown option %s", path);
                }
-               path = prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
-               if (!verify_path(path)) {
-                       fprintf(stderr, "Ignoring path %s\n", argv[i]);
-                       continue;
-               }
-               if (force_remove) {
-                       if (remove_file_from_cache(path))
-                               die("git-update-index: unable to remove %s", path);
-                       continue;
+               update_one(path, prefix, prefix_length);
+       }
+       if (read_from_stdin) {
+               struct strbuf buf;
+               strbuf_init(&buf);
+               while (1) {
+                       read_line(&buf, stdin, line_termination);
+                       if (buf.eof)
+                               break;
+                       update_one(buf.buf, prefix, prefix_length);
                }
-               if (add_file_to_cache(path))
-                       die("Unable to process file %s", path);
        }
        if (write_cache(newfd, active_cache, active_nr) ||
            commit_index_file(&cache_file))