X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=src%2Fcoloredstderr.c;h=c1522186592a91bbfece42a510c5e77018d9257b;hb=7c5d6fce3a6f52243948e3eae452acb968d78469;hp=10b83be2db01d074bb5b5f5255ecbc5aeda1a805;hpb=96710bc3fa919e221338ef96686e80ba590d3b77;p=coloredstderr%2Fcoloredstderr.git

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index 10b83be..c152218 100644
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -230,6 +230,10 @@ HOOK_FILE1(int, putchar_unlocked, stdout,
 HOOK_FILE1(int, puts_unlocked, stdout,
            const char *, s)
 
+/* perror(3) */
+HOOK_VOID1(void, perror, STDERR_FILENO,
+           const char *, s)
+
 
 /* Hook functions which duplicate file descriptors to track them. */
 
@@ -322,3 +326,23 @@ int fclose(FILE *fp) {
     close_fd(fileno(fp));
     return real_fclose(fp);
 }
+
+
+/* Hook functions which are necessary for correct tracking. */
+
+#if defined(HAVE_VFORK) && defined(HAVE_FORK)
+pid_t vfork(void) {
+    /* vfork() is similar to fork() but the address space is shared between
+     * father and child. It's designed for fork()/exec() usage because it's
+     * faster than fork(). However according to the POSIX standard the "child"
+     * isn't allowed to perform any memory-modifications before the exec()
+     * (except the pid_t result variable of vfork()).
+     *
+     * As some programs don't adhere to the standard (e.g. the "child" closes
+     * or dups a descriptor before the exec()) and this breaks our tracking of
+     * file descriptors (e.g. it gets closed in the parent as well), we just
+     * fork() instead. This is in compliance with the POSIX standard and as
+     * most systems use copy-on-write anyway not a performance issue. */
+    return fork();
+}
+#endif