1 files changed, 104 insertions, 0 deletions
diff --git a/lib/libdpv/util.c b/lib/libdpv/util.c
new file mode 100644
index 000000000000..4b2393b45821
--- /dev/null
+++ b/lib/libdpv/util.c
@@ -0,0 +1,104 @@
+/*-
+ * Copyright (c) 2013-2018 Devin Teske <dteske@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 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, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#include <err.h>
+#include <limits.h>
+#include <spawn.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "util.h"
+
+extern char **environ;
+static char cmdbuf[CMDBUFMAX]	= "";
+static char shellcmd[PATH_MAX]	= PATH_SHELL;
+static char *shellcmd_argv[6]	= {
+	shellcmd,
+	__DECONST(char *, "-c"),
+	cmdbuf,
+	__DECONST(char *, "--"),
+	shellcmd,
+	NULL,
+};
+
+/*
+ * Spawn a sh(1) command. Writes the resulting process ID to the pid_t pointed
+ * at by `pid'. Returns a file descriptor (int) suitable for writing data to
+ * the spawned command (data written to file descriptor is seen as standard-in
+ * by the spawned sh(1) command). Returns `-1' if unable to spawn command.
+ *
+ * If cmd contains a single "%s" sequence, replace it with label if non-NULL.
+ */
+int
+shell_spawn_pipecmd(const char *cmd, const char *label, pid_t *pid)
+{
+	int error;
+	int len;
+	posix_spawn_file_actions_t action;
+#if SHELL_SPAWN_DEBUG
+	unsigned int i;
+#endif
+	int stdin_pipe[2] = { -1, -1 };
+
+	/* Populate argument array */
+	if (label != NULL && fmtcheck(cmd, "%s") == cmd)
+		len = snprintf(cmdbuf, CMDBUFMAX, cmd, label);
+	else
+		len = snprintf(cmdbuf, CMDBUFMAX, "%s", cmd);
+	if (len >= CMDBUFMAX) {
+		warnx("%s:%d:%s: cmdbuf[%u] too small to hold cmd argument",
+		    __FILE__, __LINE__, __func__, CMDBUFMAX);
+		return (-1);
+	}
+
+	/* Open a pipe to communicate with [X]dialog(1) */
+	if (pipe(stdin_pipe) < 0)
+		err(EXIT_FAILURE, "%s: pipe(2)", __func__);
+
+	/* Fork sh(1) process */
+#if SHELL_SPAWN_DEBUG
+	fprintf(stderr, "%s: spawning `", __func__);
+	for (i = 0; shellcmd_argv[i] != NULL; i++) {
+		if (i == 0)
+			fprintf(stderr, "%s", shellcmd_argv[i]);
+		else if (i == 2)
+			fprintf(stderr, " '%s'", shellcmd_argv[i]);
+		else
+			fprintf(stderr, " %s", shellcmd_argv[i]);
+	}
+	fprintf(stderr, "'\n");
+#endif
+	posix_spawn_file_actions_init(&action);
+	posix_spawn_file_actions_adddup2(&action, stdin_pipe[0], STDIN_FILENO);
+	posix_spawn_file_actions_addclose(&action, stdin_pipe[1]);
+	error = posix_spawnp(pid, shellcmd, &action,
+	    (const posix_spawnattr_t *)NULL, shellcmd_argv, environ);
+	if (error != 0) err(EXIT_FAILURE, "%s", shellcmd);
+
+	return stdin_pipe[1];
+}