gshell.c

/*
 * Shell utility functions.
 *
 * Author:
 *   Gonzalo Paniagua Javier (gonzalo@novell.com
 *
 * (C) 2006 Novell, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#include <stdio.h>
#include <glib.h>

static int
split_cmdline (const gchar *cmdline, GPtrArray *array, GError **error)
{
	gchar *ptr;
	gchar c;
	gboolean escaped = FALSE, fresh = TRUE;
	gchar quote_char = '\0';
	GString *str;

	str = g_string_new ("");
	ptr = (gchar *) cmdline;
	while ((c = *ptr++) != '\0') {
		if (escaped) {
			/*
			 * \CHAR is only special inside a double quote if CHAR is
			 * one of: $`"\ and newline
			 */
			if (quote_char == '\"'){
				if (!(c == '$' || c == '`' || c == '"' || c == '\\'))
					g_string_append_c (str, '\\');
				g_string_append_c (str, c);
			} else {
				if (!g_ascii_isspace (c))
					g_string_append_c (str, c);
			}
			escaped = FALSE;
		} else if (quote_char) {
			if (c == quote_char) {
				quote_char = '\0';
				if (fresh && (g_ascii_isspace (*ptr) || *ptr == '\0')){
					g_ptr_array_add (array, g_string_free (str, FALSE));
					str = g_string_new ("");
				}
			} else if (c == '\\'){
				escaped = TRUE;
			} else 
				g_string_append_c (str, c);
		} else if (g_ascii_isspace (c)) {
			if (str->len > 0) {
				g_ptr_array_add (array, g_string_free (str, FALSE));
				str = g_string_new ("");
			}
		} else if (c == '\\') {
			escaped = TRUE;
		} else if (c == '\'' || c == '"') {
			fresh = str->len == 0;
			quote_char = c;
		} else {
			g_string_append_c (str, c);
		}
	}

	if (escaped) {
		if (error)
			*error = g_error_new (G_LOG_DOMAIN, 0, "Unfinished escape.");
		g_string_free (str, TRUE);
		return -1;
	}

	if (quote_char) {
		if (error)
			*error = g_error_new (G_LOG_DOMAIN, 0, "Unfinished quote.");
		g_string_free (str, TRUE);
		return -1;
	}

	if (str->len > 0) {
		g_ptr_array_add (array, g_string_free (str, FALSE));
	} else {
		g_string_free (str, TRUE);
	}
	g_ptr_array_add (array, NULL);
	return 0;
}

gboolean
g_shell_parse_argv (const gchar *command_line, gint *argcp, gchar ***argvp, GError **error)
{
	GPtrArray *array;
	gint argc;
	gchar **argv;

	g_return_val_if_fail (command_line, FALSE);
	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

	array = g_ptr_array_new();
	if (split_cmdline (command_line, array, error)) {
		g_ptr_array_add (array, NULL);
		g_strfreev ((gchar **) array->pdata);
		g_ptr_array_free (array, FALSE);
		return FALSE;
	}

	argc = array->len;
	argv = (gchar **) array->pdata;

	if (argc == 1) {
		g_strfreev (argv);
		g_ptr_array_free (array, FALSE);
		return FALSE;
	}

	if (argcp) {
		*argcp = array->len - 1;
	}

	if (argvp) {
		*argvp = argv;
	} else {
		g_strfreev (argv);
	}

	g_ptr_array_free (array, FALSE);
	return TRUE;
}

gchar *
g_shell_quote (const gchar *unquoted_string)
{
	GString *result = g_string_new ("'");
	const gchar *p;
	
	for (p = unquoted_string; *p; p++){
		if (*p == '\'')
			g_string_append (result, "'\\'");
		g_string_append_c (result, *p);
	}
	g_string_append_c (result, '\'');
	return g_string_free (result, FALSE);
}

gchar *
g_shell_unquote (const gchar *quoted_string, GError **error)
{
	GString *result;
	const char *p;
	int do_unquote = 0;

	if (quoted_string == NULL)
		return NULL;
	
	/* Quickly try to determine if we need to unquote or not */
	for (p = quoted_string; *p; p++){
		if (*p == '\'' || *p == '"' || *p == '\\'){
			do_unquote = 1;
			break;
		}
	}
	
	if (!do_unquote)
		return g_strdup (quoted_string);

	/* We do need to unquote */
	result = g_string_new ("");
	for (p = quoted_string; *p; p++){

		if (*p == '\''){
			/* Process single quote, not even \ is processed by glib's version */
			for (p++; *p; p++){
				if (*p == '\'')
					break;
				g_string_append_c (result, *p);
			}
			if (!*p){
				g_set_error (error, 0, 0, "Open quote");
				return NULL;
			}
		} else if (*p == '"'){
			/* Process double quote, allows some escaping */
			for (p++; *p; p++){
				if (*p == '"')
					break;
				if (*p == '\\'){
					p++;
					if (*p == 0){
						g_set_error (error, 0, 0, "Open quote");
						return NULL;
					}
					switch (*p){
					case '$':
					case '"':
					case '\\':
					case '`':
						break;
					default:
						g_string_append_c (result, '\\');
						break;
					}
				} 
				g_string_append_c (result, *p);
			}
			if (!*p){
				g_set_error (error, 0, 0, "Open quote");
				return NULL;
			}
		} else if (*p == '\\'){
			char c = *(++p);
			if (!(c == '$' || c == '"' || c == '\\' || c == '`' || c == '\'' || c == 0 ))
				g_string_append_c (result, '\\');
			if (c == 0)
				break;
			else
				g_string_append_c (result, c);
		} else
			g_string_append_c (result, *p);
	}
	return g_string_free (result, FALSE);
}

#if JOINT_TEST
/*
 * This test is designed to be built with the 2 glib/eglib to compare
 */

char *args [] = {
	"\\",
	"\"Foo'bar\"",
	"'foo'",
	"'fo\'b'",
	"'foo\"bar'",
	"'foo' dingus bar",
	"'foo' 'bar' 'baz'",
	"\"foo\" 'bar' \"baz\"",
	"\"f\\$\\\'",
	"\"\\",
	"\\\\",
	"'\\\\'",
	"\"f\\$\"\\\"\\\\", //  /\\\"\\\\"
	"'f\\$'\\\"\\\\", 
	"'f\\$\\\\'", 
	NULL
};


int
main ()
{
	char **s = args;
	int i;
	
	while (*s){
		char *r1 = g_shell_unquote (*s, NULL);
		char *r2 = g2_shell_unquote (*s, NULL);
		char *ok = r1 == r2 ? "ok" : (r1 != NULL && r2 != NULL && strcmp (r1, r2) == 0) ? "ok" : "fail";
		
		printf ("%s [%s] -> [%s] - [%s]\n", ok, *s, r1, r2);
		s++;
	}
	return;
	char buffer [10];
	buffer [0] = '\"';
	buffer [1] = '\\';
	buffer [3] = '\"';
	buffer [4] = 0;
	
	for (i = 32; i < 255; i++){
		buffer [2] = i;
		printf ("%d [%s] -> [%s]\n", i, buffer, g_shell_unquote (buffer, NULL));
	}
}
#endif