From 14709b3d5c63bc45a8f0bce53133f65c5543352d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20Mei=C3=9Fner?= <florian.meissner@mailbox.org>
Date: Mon, 29 May 2023 20:54:34 +0200
Subject: [PATCH] system(): on command == NULL, return nonzero if shell exists
---
src/header/stdlib/mod.rs | 16 +++++++++++-----
tests/expected/bins_static/stdlib/system.stdout | 1 +
tests/stdlib/system.c | 12 +++++++++++-
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/src/header/stdlib/mod.rs b/src/header/stdlib/mod.rs
index bf290f69..7ce19825 100644
--- a/src/header/stdlib/mod.rs
+++ b/src/header/stdlib/mod.rs
@@ -1170,13 +1170,19 @@ pub unsafe extern "C" fn strtoll(
pub unsafe extern "C" fn system(command: *const c_char) -> c_int {
//TODO: share code with popen
+ // handle shell detection on command == NULL
+ if command.is_null() {
+ let status = system("exit 0\0".as_ptr() as *const c_char);
+ if status == 0 {
+ return 1;
+ } else {
+ return 0;
+ }
+ }
+
let child_pid = unistd::fork();
if child_pid == 0 {
- let command_nonnull = if command.is_null() {
- "exit 0\0".as_ptr()
- } else {
- command as *const u8
- };
+ let command_nonnull = command as *const u8;
let shell = "/bin/sh\0".as_ptr();
diff --git a/tests/expected/bins_static/stdlib/system.stdout b/tests/expected/bins_static/stdlib/system.stdout
index a6d3f18a..90f99da2 100644
--- a/tests/expected/bins_static/stdlib/system.stdout
+++ b/tests/expected/bins_static/stdlib/system.stdout
@@ -1 +1,2 @@
+shell found: 1
test of system
diff --git a/tests/stdlib/system.c b/tests/stdlib/system.c
index 8b7d0220..821c216f 100644
--- a/tests/stdlib/system.c
+++ b/tests/stdlib/system.c
@@ -3,6 +3,16 @@
#include "test_helpers.h"
int main(void) {
- int status = system("echo test of system");
+ // testing shell detection
+ // this means, because we don't detect if a shell actually exists but just assume it does, this test case breaks in
+ // environments without `sh`. I think that is a reasonable tradeoff.
+ // (And if there isn't a shell, system() won't work anyways)
+ int status = system(NULL);
+ printf("shell found: %i\n", status);
+ fflush(stdout);
+ ERROR_IF(system, status, == 0);
+
+ // base case
+ status = system("echo test of system");
ERROR_IF(system, status, == -1);
}
--
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