From 80ac731c907c04f60148a696162cb95d7cedc90a Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Thu, 1 Oct 2020 10:09:05 -0400
Subject: util: Move redirect() and isopen() to main.c

---
 main.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'main.c')

diff --git a/main.c b/main.c
index 70f4d8b..f77d787 100644
--- a/main.c
+++ b/main.c
@@ -60,6 +60,28 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+/**
+ * Check if a file descriptor is open.
+ */
+static bool isopen(int fd) {
+	return fcntl(fd, F_GETFD) >= 0 || errno != EBADF;
+}
+
+/**
+ * Open a file and redirect it to a particular descriptor.
+ */
+static int redirect(int fd, const char *path, int flags) {
+	int ret = open(path, flags);
+
+	if (ret >= 0 && ret != fd) {
+		int orig = ret;
+		ret = dup2(orig, fd);
+		close(orig);
+	}
+
+	return ret;
+}
+
 /**
  * Make sure the standard streams std{in,out,err} are open.  If they are not,
  * future open() calls may use those file descriptors, and std{in,out,err} will
-- 
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