1 files changed, 116 insertions, 0 deletions
diff --git a/lib/fpopen.c b/lib/fpopen.c
new file mode 100644
index 0000000..60af208
--- /dev/null
+++ b/lib/fpopen.c
@@ -0,0 +1,116 @@
+/*
+ * fpopen.c --- unlike the libc popen, it directly executes the
+ * command instead of call out to the shell.
+ *
+ * Copyright Theodore Ts'o, 1996-1999.
+ *
+ * Permission to use this file is granted for any purposes, as long as
+ * this copyright statement is kept intact and the author is not held
+ * liable for any damages resulting from the use of this program.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
+ * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE.
+ */
+
+#include "config.h"
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <ctype.h>
+
+#define MAX_ARGV 256
+
+extern FILE *fpopen(const char *cmd, const char *mode);
+
+FILE *fpopen(const char *cmd, const char *mode)
+{
+	char	*argv[MAX_ARGV];
+	int	i = 0;
+	char	*buf, *prog = 0;
+	char	*p;
+	int	do_stdin, do_stderr = 0;
+	int	fds[2];
+	pid_t	pid;
+
+	if (!mode) {
+		errno = EFAULT;
+		return NULL;
+	}
+
+	switch (*mode) {
+	case 'r':
+		do_stdin = 0;
+		break;
+	case 'w':
+		do_stdin = 1;
+		break;
+	default:
+		errno = EINVAL;
+		return NULL;
+	}
+	switch (*(mode+1)) {
+	case '&':
+		do_stderr = 1;
+	}
+
+	/*
+	 * Create the argv vector....
+	 */
+	buf = malloc(strlen(cmd)+1);
+	if (!buf)
+		return NULL;
+	strcpy(buf, cmd);
+	p = buf;
+	while (p && *p) {
+		if (isspace(*p)) {
+			p++;
+			continue;
+		}
+		if (i == 0)
+			prog = p;
+		argv[i++] = p;
+		p = strchr(p, ' ');
+		if (p)
+			*p++ = 0;
+	}
+
+	argv[i] = 0;
+
+	/*
+	 * Get the pipe
+	 */
+	if (pipe(fds) < 0)
+		return NULL;
+
+	/* Fork and execute the correct program. */
+	if ((pid = fork()) < 0) {
+		perror("fork");
+		return NULL;
+	} else if (pid == 0) {
+		if (do_stdin) {
+			close(fds[1]);
+			dup2(fds[0], 0);
+		} else {
+			close(fds[0]);
+			dup2(fds[1], 1);
+			if (do_stderr)
+				dup2(fds[1], 2);
+		}
+		(void) execvp(prog, argv);
+		perror(prog);
+		exit(1);
+	}
+	return fdopen(do_stdin ? fds[1] : fds[0], mode);
+}
+