builtin/show-branch: rewrite functions to work with object_id

diff --git a/run-command.h b/run-command.h
index d6868dc8c868a61fb1ccc6230f43048dd9838a24..1103805af1b01e8396de15f48fbd06f75313fb0d 100644 (file)
--- a/run-command.h
+++ b/run-command.h
@@ -52,7 +52,7 @@ int start_command(struct child_process *);
 int finish_command(struct child_process *);
 int run_command(struct child_process *);
 
-extern char *find_hook(const char *name);
+extern const char *find_hook(const char *name);
 LAST_ARG_MUST_BE_NULL
 extern int run_hook_le(const char *const *env, const char *name, ...);
 extern int run_hook_ve(const char *const *env, const char *name, va_list args);
@@ -71,6 +71,19 @@ int run_command_v_opt(const char **argv, int opt);
  */
 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
 
+/**
+ * Execute the given command, capturing its stdout in the given strbuf.
+ * Returns -1 if starting the command fails or reading fails, and otherwise
+ * returns the exit code of the command. The output collected in the
+ * buffer is kept even if the command returns a non-zero exit. The hint field
+ * gives a starting size for the strbuf allocation.
+ *
+ * The fields of "cmd" should be set up as they would for a normal run_command
+ * invocation. But note that there is no need to set cmd->out; the function
+ * sets it up for the caller.
+ */
+int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint);
+
 /*
  * The purpose of the following functions is to feed a pipe by running
  * a function asynchronously and providing output that the caller reads.