[PATCH v2 1/3] Introduce die_errno() that appends strerror(errno) to die()

[Thomas Rast <trast@student.ethz.ch>]

There are many calls to die() that do, or should, report
strerror(errno) to indicate how the syscall they guard failed.
Introduce a small helper function for this case.

Code by Jeff King and Alexander Potashev, name by Johannes Sixt.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
---
 git-compat-util.h |    1 +
 usage.c           |   13 +++++++++++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/git-compat-util.h b/git-compat-util.h
index f25f7f1..0366cde 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -162,6 +162,7 @@
 /* General helper functions */
 extern void usage(const char *err) NORETURN;
 extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
+extern void die_errno(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
diff --git a/usage.c b/usage.c
index 820d09f..1819e0a 100644
--- a/usage.c
+++ b/usage.c
@@ -60,6 +60,19 @@ void die(const char *err, ...)
 	va_end(params);
 }
 
+void die_errno(const char *err, ...)
+{
+	va_list params;
+	char msg[1024];
+
+	va_start(params, err);
+
+	vsnprintf(msg, sizeof(msg), err, params);
+	die("%s: %s", msg, strerror(errno));
+
+	va_end(params);
+}
+
 int error(const char *err, ...)
 {
 	va_list params;
-- 
1.6.3.2.288.g40844