Add dirname(1).

doc/user-guide

@@ -155,6 +155,7 @@ Sortix comes with a number of home-made programs. Here is an overview:
 * `conway` - game of life simulator
 * `cp` - copy file
 * `date` - display current time and date
+* `dirname` - strip last component from file name
 * `dispd` - non-existent display server
 * `du` - report file and directory disk usage
 * `echo` - print command line arguments

utils/.gitignore

@@ -1,4 +1,5 @@
 *.o
+basename
 calc
 cat
 chmod
@@ -10,6 +11,7 @@ column
 command-not-found
 cp
 date
+dirname
 du
 echo
 editor

utils/Makefile

@@ -15,6 +15,7 @@ CPPFLAGS:=$(CPPFLAGS) -DVERSIONSTR=\"$(VERSION)\"
 CXXFLAGS:=$(CXXFLAGS) -Wall -Wextra -fno-exceptions -fno-rtti
 
 BINARIES:=\
+basename \
 calc \
 cat \
 chmod \
@@ -26,6 +27,7 @@ column \
 command-not-found \
 cp \
 date \
+dirname \
 du \
 echo \
 editor \

utils/dirname.cpp

@@ -0,0 +1,133 @@
+/*******************************************************************************
+
+    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/>.
+
+    dirname.cpp
+    Strip last component from file name.
+
+*******************************************************************************/
+
+#include <errno.h>
+#include <error.h>
+#include <libgen.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void do_dirname(char* path, bool zero)
+{
+	const char* name = dirname(path);
+	fputs(name, 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 [OPTION] NAME...\n", argv0);
+	fprintf(fp, "Output each NAME with its last non-slash component and trailing slashes\n");
+	fprintf(fp, "removed; if NAME contains no /'s, output '.' (meaning the current directory).\n");
+	fprintf(fp, "\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/          -> \"/usr\"\n", argv0);
+	fprintf(fp, "  %s dir1/str dir2/str  -> \"dir1\" followed by \"dir2\"\n", argv0);
+	fprintf(fp, "  %s stdio.h            -> \".\"\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 zero = false;
+
+	const char* argv0 = argv[0];
+	for ( int i = 1; i < argc; i++ )
+	{
+		const char* arg = argv[i];
+		if ( arg[0] != '-' || !arg[1] )
+			continue;
+		argv[i] = NULL;
+		if ( !strcmp(arg, "--") )
+			break;
+		if ( arg[1] != '-' )
+		{
+			while ( char c = *++arg ) switch ( c )
+			{
+			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, "--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);
+	}
+
+	for ( int i = 1; i < argc; i++ )
+		do_dirname(argv[i], zero);
+
+	if ( fflush(stdout) == EOF )
+		return 1;
+	if ( ferror(stdout) )
+		return 1;
+
+	return 0;
+}