run-command: be more informative about what failed

diff --git a/usage.c b/usage.c
index b5e67e3d0d4a46a69d72371f4c6a0002e40a0bf1..a2a667800474e315a362e1d0623c17dafaad1022 100644 (file)
--- a/usage.c
+++ b/usage.c
@@ -4,6 +4,7 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "git-compat-util.h"
+#include "cache.h"
 
 void vreportf(const char *prefix, const char *err, va_list params)
 {
@@ -12,6 +13,18 @@ void vreportf(const char *prefix, const char *err, va_list params)
        fprintf(stderr, "%s%s\n", prefix, msg);
 }
 
+void vwritef(int fd, const char *prefix, const char *err, va_list params)
+{
+       char msg[4096];
+       int len = vsnprintf(msg, sizeof(msg), err, params);
+       if (len > sizeof(msg))
+               len = sizeof(msg);
+
+       write_in_full(fd, prefix, strlen(prefix));
+       write_in_full(fd, msg, len);
+       write_in_full(fd, "\n", 1);
+}
+
 static NORETURN void usage_builtin(const char *err, va_list params)
 {
        vreportf("usage: ", err, params);
@@ -46,6 +59,11 @@ void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list param
        die_routine = routine;
 }
 
+void set_error_routine(void (*routine)(const char *err, va_list params))
+{
+       error_routine = routine;
+}
+
 void NORETURN usagef(const char *err, ...)
 {
        va_list params;