[PATCH v3 1/3] Introduce die_errno() that appends strerror(errno) to die()
- From
Thomas Rast <trast@student.ethz.ch>
- Date
- Jun 8, 2009, 21:02 UTC
- Message-ID
- <5f43aa9d0b69e99600a73bddd4c93217608ab661.1244494647.git.trast@student.ethz.ch>
- In-Reply-To
- <cover.1244494646.git.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.
Note:
- POSIX says vsnprintf can modify errno in some unlikely cases, so we have to use errno early.
- We take some care to pass the original format to die_routine(), in case someone wants to call die_errno() with custom format characters.
Signed-off-by: Thomas Rast <trast@student.ethz.ch> --- git-compat-util.h | 1 + usage.c | 12 ++++++++++++ 2 files changed, 13 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..fd936a1 100644 --- a/usage.c +++ b/usage.c @@ -60,6 +60,18 @@ void die(const char *err, ...) va_end(params); } +void die_errno(const char *fmt, ...) +{ + va_list params; + char fmt_with_err[1024]; + + snprintf(fmt_with_err, sizeof(fmt_with_err), "%s: %s", fmt, strerror(errno)); + + va_start(params, fmt); + die_routine(fmt_with_err, params); + va_end(params); +} + int error(const char *err, ...) { va_list params;
-- 1.6.3.2.333.g27636