Safeguarded dup2 and close sequence in getcmd

4 years ago · e6844edbf1
parent d4a726ad78
commit e6844edbf1
1 changed files with 6 additions and 4 deletions
--- a/dwmblocks.c
+++ b/dwmblocks.c
@ -81,11 +81,13 @@ getcmd(Block *block, int sigval)
                case 0:
                        close(ConnectionNumber(dpy));
                        close(fd[0]);
-                        if (dup2(fd[1], STDOUT_FILENO) != STDOUT_FILENO) {
-                                perror("getcmd - child - dup2");
-                                exit(1);
+                        if (fd[1] != STDOUT_FILENO) {
+                                if (dup2(fd[1], STDOUT_FILENO) != STDOUT_FILENO) {
+                                        perror("getcmd - child - dup2");
+                                        exit(1);
+                                }
+                                close(fd[1]);
                        }
-                        close(fd[1]);
                        if (sigval == NILL) {
                                char *arg[] = { block->pathu, NULL };