Add basename(1).

doc/user-guide

@@ -141,6 +141,7 @@ Included Programs
 Sortix comes with a number of home-made programs. Here is an overview:
 
 * `asteroids` - remake of the classic asteroids game
+* `basename` - strip directory from filenames
 * `benchctxswitch` - useless benchmark
 * `benchsyscall` - slightly less useless benchmark
 * `calc` - reverse polish calculator

utils/basename.cpp

@@ -0,0 +1,195 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+
+    basename.cpp
+    Strip directory and suffix from filenames.
+
+*******************************************************************************/
+
+#include <errno.h>
+#include <error.h>
+#include <libgen.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void do_basename(char* path, const char* suffix, bool zero)
+{
+	if ( path[0] )
+	{
+		const char* name = basename(path);
+		size_t name_length = strlen(name);
+		size_t suffix_length = suffix ? strlen(suffix) : 0;
+		if ( suffix && suffix_length <= name_length &&
+			 !strcmp(name + name_length - suffix_length, suffix) )
+			name_length -= suffix_length;
+		fwrite(name, sizeof(char), name_length, stdout);
+	}
+	fputc(zero ? '\0' : '\n', stdout);
+}
+
+static void compact_arguments(int* argc, char*** argv)
+{
+	for ( int i = 0; i < *argc; i++ )
+	{
+		while ( i < *argc && !(*argv)[i] )
+		{
+			for ( int n = i; n < *argc; n++ )
+				(*argv)[n] = (*argv)[n+1];
+			(*argc)--;
+		}
+	}
+}
+
+static void help(FILE* fp, const char* argv0)
+{
+	fprintf(fp, "Usage: %s NAME [SUFFIX]\n", argv0);
+	fprintf(fp, "  or:  %s OPTION... NAME...\n", argv0);
+	fprintf(fp, "Print NAME with any leading directory components removed.\n");
+	fprintf(fp, "If specified, also remove a trailing SUFFIX.\n");
+	fprintf(fp, "\n");
+	fprintf(fp, "  -a, --multiple       support multiple arguments and treat each as a NAME\n");
+	fprintf(fp, "  -s, --suffix=SUFFIX  remove a trailing SUFFIX\n");
+	fprintf(fp, "  -z, --zero           separate output with NUL rather than newline\n");
+	fprintf(fp, "      --help           display this help and exit\n");
+	fprintf(fp, "      --version        output version information and exit\n");
+	fprintf(fp, "\n");
+	fprintf(fp, "Examples:\n");
+	fprintf(fp, "  %s /usr/bin/sort          -> \"sort\"\n", argv0);
+	fprintf(fp, "  %s include/stdio.h .h     -> \"stdio\"\n", argv0);
+	fprintf(fp, "  %s -s .h include/stdio.h  -> \"stdio\"\n", argv0);
+	fprintf(fp, "  %s -a any/str1 any/str2   -> \"str1\" followed by \"str2\"\n", argv0);
+
+}
+
+static void version(FILE* fp, const char* argv0)
+{
+	fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
+	fprintf(fp, "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n");
+	fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
+	fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
+}
+
+int main(int argc, char* argv[])
+{
+	setlocale(LC_ALL, "");
+
+	bool multiple = false;
+	const char* suffix = NULL;
+	bool zero = false;
+
+	const char* argv0 = argv[0];
+	for ( int i = 1; i < argc; i++ )
+	{
+		const char* arg = argv[i];
+		if ( arg[0] != '-' || !arg[1] )
+			break; /* Stop after first non-option. */
+		argv[i] = NULL;
+		if ( !strcmp(arg, "--") )
+			break;
+		if ( arg[1] != '-' )
+		{
+			while ( char c = *++arg ) switch ( c )
+			{
+			case 'a': multiple = true; break;
+			case 's':
+				if ( !*(suffix = arg + 1) )
+				{
+					if ( i + 1 == argc )
+					{
+						error(0, 0, "option requires an argument -- 's'");
+						fprintf(stderr, "Try `%s --help' for more information.\n", argv[0]);
+						exit(1);
+					}
+					suffix = argv[i+1];
+					argv[++i] = NULL;
+				}
+				arg = "s";
+				break;
+			case 'z': zero = true; break;
+			default:
+				fprintf(stderr, "%s: unknown option -- '%c'\n", argv0, c);
+				help(stderr, argv0);
+				exit(1);
+			}
+		}
+		else if ( !strcmp(arg, "--help") )
+			help(stdout, argv0), exit(0);
+		else if ( !strcmp(arg, "--version") )
+			version(stdout, argv0), exit(0);
+		else if ( !strcmp(arg, "--multiple") )
+			multiple = true;
+		else if ( !strncmp(arg, "--suffix=", strlen("--suffix=")) )
+			suffix = arg + strlen("--suffix=");
+		else if ( !strcmp(arg, "--suffix") )
+		{
+			if ( i + 1 == argc )
+			{
+				error(0, 0, "option '--suffix' requires an argument");
+				fprintf(stderr, "Try `%s --help' for more information.\n", argv[0]);
+				exit(125);
+			}
+			suffix = argv[i+1];
+			argv[++i] = NULL;
+		}
+		else if ( !strcmp(arg, "--zero") )
+			zero = true;
+		else
+		{
+			fprintf(stderr, "%s: unknown option: %s\n", argv0, arg);
+			help(stderr, argv0);
+			exit(1);
+		}
+	}
+
+	compact_arguments(&argc, &argv);
+
+	if ( argc <= 1 )
+	{
+		error(0, 0, "missing operand");
+		fprintf(stderr, "Try `%s --help' for more information.\n", argv[0]);
+		exit(1);
+	}
+
+	if ( multiple || suffix )
+	{
+		for ( int i = 1; i < argc; i++ )
+			do_basename(argv[i], suffix, zero);
+	}
+	else
+	{
+		if ( 4 <= argc )
+		{
+			error(0, 0, "extra operand `%s'", argv[3]);
+			fprintf(stderr, "Try `%s --help' for more information.\n", argv[0]);
+			exit(1);
+		}
+
+		if ( 3 <= argc )
+			suffix = argv[2];
+
+		do_basename(argv[1], suffix, zero);
+	}
+
+	if ( fflush(stdout) == EOF )
+		return 1;
+	if ( ferror(stdout) )
+		return 1;
+
+	return 0;
+}