Add "unpack-file" helper that unpacks a sha1 blob into a tmpfile.

[git.git] / unpack-file.c

diff --git a/unpack-file.c b/unpack-file.c
new file mode 100644 (file)
index 0000000..6ff3d51
--- /dev/null
+++ b/unpack-file.c
@@ -0,0 +1,34 @@
+#include "cache.h"
+
+static char *create_temp_file(unsigned char *sha1)
+{
+       static char path[50];
+       void *buf;
+       char type[100];
+       unsigned long size;
+       int fd;
+
+       buf = read_sha1_file(sha1, type, &size);
+       if (!buf || strcmp(type, "blob"))
+               die("unable to read blob object %s", sha1_to_hex(sha1));
+
+       strcpy(path, ".merge_file_XXXXXX");
+       fd = mkstemp(path);
+       if (fd < 0)
+               die("unable to create temp-file");
+       if (write(fd, buf, size) != size)
+               die("unable to write temp-file");
+       close(fd);
+       return path;
+}
+
+int main(int argc, char **argv)
+{
+       unsigned char sha1[20];
+
+       if (argc != 2 || get_sha1_hex(argv[1], sha1))
+               usage("unpack-file.c <sha1>");
+
+       puts(create_temp_file(sha1));
+       return 0;
+}