From 8bf49d16a637cca0cd116450dfcabc4c941baf6c Mon Sep 17 00:00:00 2001
From: ticktock35 <ticktock35@e8e0d7a0-c8d9-11dd-a880-a1081c7ac358>
Date: Sun, 14 Dec 2008 23:10:56 -0500
Subject: * Add ipkg for future development

git-svn-id: http://opkg.googlecode.com/svn/trunk@3 e8e0d7a0-c8d9-11dd-a880-a1081c7ac358
---
(limited to 'xsystem.c')

diff --git a/xsystem.c b/xsystem.c
new file mode 100644
index 0000000..75ce480
--- /dev/null
+++ b/xsystem.c
@@ -0,0 +1,64 @@
+/* xsystem.c - system(3) with error messages
+
+   Carl D. Worth
+
+   Copyright (C) 2001 University of Southern California
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+*/
+
+#include "ipkg.h"
+#include <sys/wait.h>
+
+#include "xsystem.h"
+
+/* XXX: FEATURE: I shouldn't actually use system(3) at all. I don't
+   really need the /bin/sh invocation which takes resources and
+   introduces security problems. I should switch all of this to a sort
+   of execl() or execv() interface/implementation.
+*/
+
+/* Like system(3), but with error messages printed if the fork fails
+   or if the child process dies due to an uncaught signal. Also, the
+   return value is a bit simpler:
+
+   -1 if there was any problem
+   Otherwise, the 8-bit return value of the program ala WEXITSTATUS
+   as defined in <sys/wait.h>.
+*/
+int xsystem(const char *cmd)
+{
+    int err;
+
+    err = system(cmd);
+
+    if (err == -1) {
+	fprintf(stderr, "%s: ERROR: fork failed before execution: `%s'\n",
+		__FUNCTION__, cmd);
+	return -1;
+    }
+
+    if (WIFSIGNALED(err)) {
+	fprintf(stderr, "%s: ERROR: Child process died due to signal %d: `%s'\n",
+		__FUNCTION__, WTERMSIG(err), cmd);
+	return -1;
+    }
+
+    if (WIFEXITED(err)) {
+	/* Normal child exit */
+	return WEXITSTATUS(err);
+    }
+
+    fprintf(stderr, "%s: ERROR: Received unintelligible return value from system: %d",
+	    __FUNCTION__, err);
+    return -1;
+}
+	 
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