sandbox: add proper option parsing

This lays the groundwork for adding more runtime options.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

4 files changed, 125 insertions, 40 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index c3c1f45..24ffdcf 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -11,5 +11,6 @@ AM_CPPFLAGS = \
 sandbox_LDADD = $(top_builddir)/libsbutil/libsbutil.la $(LIBDL)
 sandbox_SOURCES = \
 	environ.c \
+	options.c \
 	sandbox.h \
 	sandbox.c
diff --git a/src/options.c b/src/options.c
new file mode 100644
index 0000000..10f937c
--- /dev/null
+++ b/src/options.c
@@ -0,0 +1,116 @@
+/*
+ * Handle command line arguments
+ *
+ * Copyright 1999-2015 Gentoo Foundation
+ * Licensed under the GPL-2
+ */
+
+#include "headers.h"
+#include "sbutil.h"
+#include "sandbox.h"
+
+static void show_version(void)
+{
+	puts(
+		"Gentoo path sandbox\n"
+		" version: " PACKAGE_VERSION "\n"
+		" C lib:   " LIBC_VERSION " (" LIBC_PATH ")\n"
+		" build:   " __DATE__ " " __TIME__ "\n"
+		" contact: " PACKAGE_BUGREPORT " via http://bugs.gentoo.org/\n"
+		" rtld:    "
+#ifdef BROKEN_RTLD_NEXT
+			"next is broken ;(\n"
+#else
+			"next is OK! :D\n"
+#endif
+#ifndef SB_SCHIZO
+# define SB_SCHIZO "no"
+#endif
+		" schizo:  " SB_SCHIZO "\n"
+		"\nconfigured with these options:\n"
+		SANDBOX_CONFIGURE_OPTS
+	);
+	exit(0);
+}
+
+#define PARSE_FLAGS "+hV"
+#define a_argument required_argument
+static struct option const long_opts[] = {
+	{"help",          no_argument, NULL, 'h'},
+	{"version",       no_argument, NULL, 'V'},
+	{NULL,            no_argument, NULL, 0x0}
+};
+static const char * const opts_help[] = {
+	"Print this help and exit",
+	"Print version and exit",
+	NULL
+};
+
+static void show_usage(int status)
+{
+	const char a_arg[] = "<arg>";
+	size_t a_arg_len = strlen(a_arg) + 2;
+	size_t i;
+	int optlen;
+	FILE *fp = status ? stderr : stdout;
+
+	fprintf(fp,
+		"Usage: sandbox [options] [program [program args...]]\n"
+		"\n"
+		"Sandbox will start up a sandbox session and execute the specified program.\n"
+		"If no program is specified, an interactive shell is automatically launched.\n"
+		"You can use this to quickly test out sandbox behavior.\n"
+		"\n"
+		"Upon startup, initial settings are taken from these files / directories:\n"
+		"\t" SANDBOX_CONF_FILE "\n"
+		"\t" SANDBOX_CONFD_DIR "\n"
+	);
+
+	fprintf(fp, "\nOptions: -[%s]\n", PARSE_FLAGS + 1);
+	/* prescan the --long opt length to auto-align */
+	optlen = 0;
+	for (i = 0; long_opts[i].name; ++i) {
+		int l = strlen(long_opts[i].name);
+		if (long_opts[i].has_arg == a_argument)
+			l += a_arg_len;
+		optlen = MAX(l, optlen);
+	}
+
+	for (i = 0; long_opts[i].name; ++i) {
+		/* first output the short flag if it has one */
+		if (long_opts[i].val > '~' || long_opts[i].val < ' ')
+			printf("      ");
+		else
+			printf("  -%c, ", long_opts[i].val);
+
+		/* then the long flag */
+		if (long_opts[i].has_arg == no_argument)
+			printf("--%-*s", optlen, long_opts[i].name);
+		else
+			printf("--%s %s %*s", long_opts[i].name, a_arg,
+				(int)(optlen - strlen(long_opts[i].name) - a_arg_len), "");
+
+		/* finally the help text */
+		printf(" * %s\n", opts_help[i]);
+	}
+
+	fprintf(fp, "\nContact: " PACKAGE_BUGREPORT " via http://bugs.gentoo.org/\n");
+
+	exit(status);
+}
+
+void parseargs(int argc, char *argv[])
+{
+	int i;
+
+	while ((i = getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
+		switch (i) {
+		case 'V':
+			show_version();
+		case 'h':
+			show_usage(0);
+		case '?':
+			show_usage(1);
+		}
+	}
+}
diff --git a/src/sandbox.c b/src/sandbox.c
index c2a1d25..15c87b2 100644
--- a/src/sandbox.c
+++ b/src/sandbox.c
@@ -204,49 +204,14 @@ int main(int argc, char **argv)
 
 	char *run_str = "-c";
 
+	/* Process the sandbox opts and leave argc/argv for the target. */
+	parseargs(argc, argv);
+	argc -= optind - 1;
+	argv[optind - 1] = argv[0];
+	argv += optind - 1;
 	/* Only print info if called with no arguments .... */
 	if (argc < 2)
 		print_debug = 1;
-	else {
-		/* handle a few common options */
-		if (!strcmp(argv[1], "--version") || !strcmp(argv[1], "-V")) {
-			puts(
-				"Gentoo path sandbox\n"
-				" version: " PACKAGE_VERSION "\n"
-				" C lib:   " LIBC_VERSION " (" LIBC_PATH ")\n"
-				" build:   " __DATE__ " " __TIME__ "\n"
-				" contact: " PACKAGE_BUGREPORT " via http://bugs.gentoo.org/\n"
-				" rtld:    "
-#ifdef BROKEN_RTLD_NEXT
-					"next is broken ;(\n"
-#else
-					"next is OK! :D\n"
-#endif
-#ifndef SB_SCHIZO
-# define SB_SCHIZO "no"
-#endif
-				" schizo:  " SB_SCHIZO "\n"
-				"\nconfigured with these options:\n"
-				SANDBOX_CONFIGURE_OPTS
-			);
-			return 0;
-		} else if (!strcmp(argv[1], "--help") || !strcmp(argv[1], "-h")) {
-			puts(
-				"Usage: sandbox [program [program args...]]\n"
-				"\n"
-				"Sandbox will start up a sandbox session and execute the specified program.\n"
-				"If no program is specified, an interactive shell is automatically launched.\n"
-				"You can use this to quickly test out sandbox behavior.\n"
-				"\n"
-				"Upon startup, initial settings are taken from these files / directories:\n"
-				"\t" SANDBOX_CONF_FILE "\n"
-				"\t" SANDBOX_CONFD_DIR "\n"
-				"\n"
-				"Contact: " PACKAGE_BUGREPORT " via http://bugs.gentoo.org/"
-			);
-			return 0;
-		}
-	}
 
 	dputs(sandbox_banner);
 
diff --git a/src/sandbox.h b/src/sandbox.h
index c0c4315..361d468 100644
--- a/src/sandbox.h
+++ b/src/sandbox.h
@@ -32,4 +32,7 @@ extern char **setup_environ(struct sandbox_info_t *sandbox_info);
 #define sb_err(fmt, args...)  _sb_err(warn, fmt, ## args)
 #define sb_perr(fmt, args...) _sb_err(pwarn, fmt, ## args)
 
+/* Option parsing related code */
+extern void parseargs(int argc, char *argv[]);
+
 #endif