cronie/SOURCES/optimization_to_close_fds.p...

41 lines
1.1 KiB
Diff

--- ./src/do_command.c 2023-09-07 09:40:32.016272074 +0200
+++ ./src/do_command.c 2023-09-07 09:43:04.938995232 +0200
@@ -30,6 +30,7 @@
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
+#include <dirent.h>
#include "externs.h"
#include "funcs.h"
@@ -239,10 +240,26 @@
{
char *shell = env_get("SHELL", jobenv);
int fd, fdmax = getdtablesize();
+ DIR *dir;
+ struct dirent *dent;
- /* close all unwanted open file descriptors */
- for(fd = STDERR + 1; fd < fdmax; fd++) {
- close(fd);
+ /*
+ * if /proc is mounted, we can optimize what fd can be closed,
+ * but if it isn't available, fall back to the previous behavior.
+ */
+ if ((dir = opendir("/proc/self/fd")) != NULL) {
+ while ((dent = readdir(dir)) != NULL) {
+ if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
+ continue;
+ fd = atoi(dent->d_name);
+ if (fd > STDERR_FILENO)
+ close(fd);
+ }
+ } else {
+ /* close all unwanted open file descriptors */
+ for(fd = STDERR + 1; fd < fdmax; fd++) {
+ close(fd);
+ }
}
#if DEBUGGING