musl - musl - an implementation of the standard library for Linux-based systems

musl - an implementation of the standard library for Linux-based systems

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author	Rich Felker <dalias@aerifal.cx>	2012年03月01日 22:08:05 -0500
committer	Rich Felker <dalias@aerifal.cx>	2012年03月01日 22:08:05 -0500
commit	899b13cae77469a9ed1f076c456b66d567af69d8 (patch)
tree	a01682acfab764f81abdc08c60ac33320e8fc93a /src
parent	051175d4fe2bdc7b09da9b303e88881ad4f936ff (diff)
download	musl-899b13cae77469a9ed1f076c456b66d567af69d8.tar.gz

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.

Diffstat (limited to 'src')

-rw-r--r--

src/unistd/getcwd.c

1 files changed, 6 insertions, 1 deletions

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 <unistd.h>

#include <errno.h>

+#include <limits.h>

+#include <string.h>

#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;

}

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