From f313a1622448de578ab0b11a881f44a02c9082e6 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 20 Jun 2012 12:07:18 -0400 Subject: [PATCH] make strerror_r behave nicer on failure if the buffer is too short, at least return a partial string. this is helpful if the caller is lazy and does not check for failure. care is taken to avoid writing anything if the buffer length is zero, and to always null-terminate when the buffer length is non-zero. --- src/string/strerror_r.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/src/string/strerror_r.c b/src/string/strerror_r.c index 6fdd4ce2..907dcf07 100644 --- a/src/string/strerror_r.c +++ b/src/string/strerror_r.c @@ -4,8 +4,14 @@ int strerror_r(int err, char *buf, size_t buflen) { char *msg = strerror(err); - if (strlen(msg) >= buflen) + size_t l = strlen(msg); + if (l >= buflen) { + if (buflen) { + memcpy(buf, msg, buflen-1); + buf[buflen-1] = 0; + } return ERANGE; - strcpy(buf, msg); + } + memcpy(buf, msg, l+1); return 0; }