Add global helpers my_system() and my_popen()

src/system/helpers.cpp

@@ -0,0 +1,115 @@
+/*
+	Neutrino-GUI  -   DBoxII-Project
+
+	Copyright (C) 2001 Steffen Hehn 'McClean'
+	Homepage: http://dbox.cyberphoria.org/
+
+	Kommentar:
+
+	Diese GUI wurde von Grund auf neu programmiert und sollte nun vom
+	Aufbau und auch den Ausbaumoeglichkeiten gut aussehen. Neutrino basiert
+	auf der Client-Server Idee, diese GUI ist also von der direkten DBox-
+	Steuerung getrennt. Diese wird dann von Daemons uebernommen.
+
+
+	License: GPL
+
+	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 of the License, 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.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <iostream>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include <system/helpers.h>
+
+int my_system(const char * cmd, const char * arg1, const char * arg2)
+{
+        int i;
+	pid_t pid;
+	int maxfd = getdtablesize();// sysconf(_SC_OPEN_MAX);
+	switch (pid = vfork())
+	{
+		case -1: /* can't vfork */
+			perror("vfork");
+			return -1;
+		case 0: /* child process */
+			for(i = 3; i < maxfd; i++)
+                                close(i);
+			if(execlp(cmd, cmd, arg1, arg2, NULL))
+			{
+				perror("exec");
+			}
+			exit(0);
+		default: /* parent returns to calling process */
+			break;
+	}
+	waitpid(pid, 0, 0);
+	return 0;
+}
+
+FILE* my_popen( pid_t& pid, const char *cmdstring, const char *type)
+{
+	int     pfd[2] ={-1,-1};
+	FILE    *fp = NULL;
+
+	/* only allow "r" or "w" */
+	if ((type[0] != 'r' && type[0] != 'w') || type[1] != 0) {
+		errno = EINVAL;     /* required by POSIX */
+		return(NULL);
+	}
+
+	if (pipe(pfd) < 0)
+		return(NULL);   /* errno set by pipe() */
+
+	if ((pid = vfork()) < 0) {
+		return(NULL);   /* errno set by vfork() */
+	} else if (pid == 0) {                           /* child */
+		if (*type == 'r') {
+			close(pfd[0]);
+			if (pfd[1] != STDOUT_FILENO) {
+				dup2(pfd[1], STDOUT_FILENO);
+				close(pfd[1]);
+			}
+		} else {
+			close(pfd[1]);
+			if (pfd[0] != STDIN_FILENO) {
+				dup2(pfd[0], STDIN_FILENO);
+				close(pfd[0]);
+			}
+		}
+		execl("/bin/sh", "sh", "-c", cmdstring, (char *)0);
+		exit(0);
+	 }
+
+	/* parent continues... */
+	if (*type == 'r') {
+		close(pfd[1]);
+		if ((fp = fdopen(pfd[0], type)) == NULL)
+			return(NULL);
+		} else {
+			close(pfd[0]);
+		if ((fp = fdopen(pfd[1], type)) == NULL)
+			return(NULL);
+	}
+	return(fp);
+}