From b875036e5a2ab569a2123abe9ebfe25258227951 Mon Sep 17 00:00:00 2001 From: Thomas Rast Date: Sat, 27 Jun 2009 17:58:44 +0200 Subject: Introduce die_errno() that appends strerror(errno) to die() 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 Signed-off-by: Junio C Hamano --- usage.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'usage.c') diff --git a/usage.c b/usage.c index 820d09f92b..fd936a1aeb 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; -- cgit v1.3 From f8b5a8e13cb4d60c8b630f92a8f07590ef218ec5 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Sat, 27 Jun 2009 17:58:45 +0200 Subject: die_errno(): double % in strerror() output just in case [tr: handle border case where % is placed at end of buffer] Signed-off-by: Junio C Hamano Signed-off-by: Thomas Rast Signed-off-by: Junio C Hamano --- usage.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'usage.c') diff --git a/usage.c b/usage.c index fd936a1aeb..b6aea45280 100644 --- a/usage.c +++ b/usage.c @@ -64,8 +64,24 @@ 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)); + char str_error[256], *err; + int i, j; + + err = strerror(errno); + for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) { + if ((str_error[j++] = err[i++]) != '%') + continue; + if (j < sizeof(str_error) - 1) { + str_error[j++] = '%'; + } else { + /* No room to double the '%', so we overwrite it with + * '\0' below */ + j--; + break; + } + } + str_error[j] = 0; + snprintf(fmt_with_err, sizeof(fmt_with_err), "%s: %s", fmt, str_error); va_start(params, fmt); die_routine(fmt_with_err, params); -- cgit v1.3