Merge pull request #6 from termux/check-executable-permission

Check executable permission of file (#5)

Author: fornwall

run-tests.sh

@@ -9,7 +9,7 @@ for f in tests/*.sh; do
 	ACTUAL_FILE=$f-actual
 
 	rm -f $ACTUAL_FILE
-	$f myarg1 myarg2 > $ACTUAL_FILE
+	$f myarg1 myarg2 &> $ACTUAL_FILE
 
 	if cmp --silent $ACTUAL_FILE $EXPECTED_FILE; then
 		printf " OK\n"

termux-exec.c

@@ -26,6 +26,9 @@ int execve(const char* filename, char* const* argv, char *const envp[])
 	char filename_buffer[512];
 	filename = termux_rewrite_executable(filename, filename_buffer, sizeof(filename_buffer));
 
+	// Error out if the file is not executable:
+	if (access(filename, X_OK) != 0) goto final;
+
 	fd = open(filename, O_RDONLY);
 	if (fd == -1) goto final;
 

tests/not-executable.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo hello

tests/not-executable.sh-expected

@@ -0,0 +1 @@
+./run-tests.sh: line 12: tests/not-executable.sh: Permission denied