From 899b13cae77469a9ed1f076c456b66d567af69d8 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 1 Mar 2012 22:08:05 -0500 Subject: [PATCH] support null buffer argument to getcwd, auto-allocating behavior this is a popular extension some programs depend on, and by using a temporary buffer and strdup rather than malloc prior to the syscall, i've avoided the dependency on free and thus minimized the bloat cost of supporting this feature. --- src/unistd/getcwd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/unistd/getcwd.c b/src/unistd/getcwd.c index b64b560f..2e540cd4 100644 --- a/src/unistd/getcwd.c +++ b/src/unistd/getcwd.c @@ -1,8 +1,13 @@ #include #include +#include +#include #include "syscall.h" char *getcwd(char *buf, size_t size) { - return syscall(SYS_getcwd, buf, size) < 0 ? NULL : buf; + char tmp[PATH_MAX]; + if (!buf) buf = tmp, size = PATH_MAX; + if (syscall(SYS_getcwd, buf, size) < 0) return 0; + return buf == tmp ? strdup(buf) : buf; }