X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=src%2Fcoloredstderr.c;h=63c4a61411b308855046b7c207e7173fda08da82;hb=d475e5ec892390e3f43c5fb4cb373cedc33211fd;hp=b16633f8534b8b7d9a1e4fdc64532a185497c598;hpb=ad50ad9c54dea706b45d63dd5fdf1e381158f83f;p=coloredstderr%2Fcoloredstderr.git

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index b16633f..63c4a61 100644
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -77,7 +77,7 @@ static int check_handle_fd(int fd) {
 
 static void dup_fd(int oldfd, int newfd) {
 #ifdef DEBUG
-    debug("%d -> %d\t\t\t[%d]\n", oldfd, newfd, getpid());
+    debug("%3d -> %3d\t\t\t[%d]\n", oldfd, newfd, getpid());
 #endif
 
     if (!initialized) {
@@ -105,7 +105,7 @@ static void dup_fd(int oldfd, int newfd) {
 
 static void close_fd(int fd) {
 #ifdef DEBUG
-    debug("%d -> .\t\t\t[%d]\n", fd, getpid());
+    debug("%3d ->   .\t\t\t[%d]\n", fd, getpid());
 #endif
 
     if (!initialized) {
@@ -326,3 +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