Redirect stdin from /dev/null for -ok and -okdir.

6 files changed, 113 insertions, 34 deletions

diff --git a/Makefile b/Makefile
index 86bf47f..5704823 100644
--- a/Makefile
+++ b/Makefile
@@ -34,7 +34,7 @@ ALL_LDFLAGS = $(ALL_CFLAGS) $(LDFLAGS)
 
 all: bfs
 
-bfs: bftw.o color.o dstring.o eval.o main.o parse.o typo.o
+bfs: bftw.o color.o dstring.o eval.o main.o parse.o typo.o util.o
 	$(CC) $(ALL_LDFLAGS) $^ -o $@
 
 release: CFLAGS := -O3 -flto -Wall -DNDEBUG
diff --git a/eval.c b/eval.c
index 54d9a7c..34343d4 100644
--- a/eval.c
+++ b/eval.c
@@ -12,6 +12,7 @@
 #include "bfs.h"
 #include "bftw.h"
 #include "dstring.h"
+#include "util.h"
 #include <assert.h>
 #include <dirent.h>
 #include <errno.h>
@@ -447,8 +448,17 @@ bool eval_exec(const struct expr *expr, struct eval_state *state) {
 			exec_chdir(ftwbuf);
 		}
 
+		if (expr->exec_flags & EXEC_CONFIRM) {
+			if (redirect(STDIN_FILENO, "/dev/null", O_RDONLY) < 0) {
+				perror("redirect()");
+				goto exit;
+			}
+		}
+
 		execvp(argv[0], argv);
 		perror("execvp()");
+
+	exit:
 		_Exit(EXIT_FAILURE);
 	}
 
diff --git a/main.c b/main.c
index 03c5020..7471156 100644
--- a/main.c
+++ b/main.c
@@ -10,6 +10,7 @@
  *********************************************************************/
 
 #include "bfs.h"
+#include "util.h"
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
@@ -17,43 +18,14 @@
 #include <unistd.h>
 
 /**
- * Check if a file descriptor is open.
- */
-static bool is_fd_open(int fd) {
-	return fcntl(fd, F_GETFD) >= 0 || errno != EBADF;
-}
-
-/**
  * Ensure that a file descriptor is open.
  */
 static int ensure_fd_open(int fd, int flags) {
-	if (is_fd_open(fd)) {
+	if (isopen(fd)) {
 		return 0;
+	} else {
+		return redirect(fd, "/dev/null", flags);
 	}
-
-	int devnull = open("/dev/null", flags);
-	if (devnull < 0) {
-		perror("open()");
-		return -1;
-	}
-
-	int ret = 0;
-
-	if (devnull != fd) {
-		// Probably not reachable
-
-		if (dup2(devnull, fd) < 0) {
-			perror("dup2()");
-			ret = -1;
-		}
-
-		if (close(devnull) != 0) {
-			perror("close()");
-			ret = -1;
-		}
-	}
-
-	return ret;
 }
 
 /**
diff --git a/tests.sh b/tests.sh
index 51f891c..87a0ea1 100755
--- a/tests.sh
+++ b/tests.sh
@@ -434,7 +434,17 @@ function test_0078() {
     ! "$BFS" "$perms" -perm +777 2>/dev/null
 }
 
-for i in {1..78}; do
+function test_0079() {
+    # -ok should close stdin for the executed command
+    yes | "$BFS" "$basic" -ok cat ';' 2>/dev/null
+}
+
+function test_0080() {
+    # -okdir should close stdin for the executed command
+    yes | "$BFS" "$basic" -okdir cat ';' 2>/dev/null
+}
+
+for i in {1..80}; do
     test="test_$(printf '%04d' $i)"
 
     if [ -t 1 ]; then
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..e0f6177
--- /dev/null
+++ b/util.c
@@ -0,0 +1,50 @@
+/*********************************************************************
+ * bfs                                                               *
+ * Copyright (C) 2016 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This program is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+#include "util.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+bool isopen(int fd) {
+	return fcntl(fd, F_GETFD) >= 0 || errno != EBADF;
+}
+
+int redirect(int fd, const char *path, int flags, ...) {
+	close(fd);
+
+	mode_t mode = 0;
+	if (flags & O_CREAT) {
+		va_list args;
+		va_start(args, flags);
+
+		// Use int rather than mode_t, because va_arg must receive a
+		// fully-promoted type
+		mode = va_arg(args, int);
+
+		va_end(args);
+	}
+
+	int ret = open(path, flags, mode);
+
+	if (ret >= 0 && ret != fd) {
+		int other = ret;
+		ret = dup2(other, fd);
+		if (close(other) != 0) {
+			ret = -1;
+		}
+	}
+
+	return ret;
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..c3b3dbe
--- /dev/null
+++ b/util.h
@@ -0,0 +1,37 @@
+/*********************************************************************
+ * bfs                                                               *
+ * Copyright (C) 2016 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This program is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+#ifndef BFS_UTIL_H
+#define BFS_UTIL_H
+
+#include <stdbool.h>
+
+/**
+ * Check if a file descriptor is open.
+ */
+bool isopen(int fd);
+
+/**
+ * Open a file and redirect it to a particular descriptor.
+ *
+ * @param fd
+ *         The file descriptor to redirect.
+ * @param path
+ *         The path to open.
+ * @param flags
+ *         The flags passed to open().
+ * @param mode
+ *         The mode passed to open() (optional).
+ * @return fd on success, -1 on failure.
+ */
+int redirect(int fd, const char *path, int flags, ...);
+
+#endif // BFS_UTIL_H