Add find(1) stub.

utils/.gitignore

@@ -28,3 +28,4 @@ rmdir
 which
 ln
 mv
+find

utils/Makefile

@@ -23,6 +23,7 @@ column \
 cp \
 echo \
 editor \
+find \
 head \
 help \
 init \

utils/find.cpp

@@ -0,0 +1,125 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    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/>.
+
+    find.cpp
+    Locate files and directories.
+
+*******************************************************************************/
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <dirent.h>
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+char* AddElemToPath(const char* path, const char* elem)
+{
+	size_t pathlen = strlen(path);
+	size_t elemlen = strlen(elem);
+	if ( pathlen && path[pathlen-1] == '/' )
+	{
+		char* ret = (char*) malloc(sizeof(char) * (pathlen + elemlen + 1));
+		stpcpy(stpcpy(ret, path), elem);
+		return ret;
+	}
+	char* ret = (char*) malloc(sizeof(char) * (pathlen + 1 + elemlen + 1));
+	stpcpy(stpcpy(stpcpy(ret, path), "/"), elem);
+	return ret;
+}
+
+const int TYPE_FILE = 1 << 0;
+const int TYPE_DIR = 1 << 1;
+
+bool Find(int dirfd, const char* relpath, const char* path, int types)
+{
+	bool ret = true;
+	int fd = openat(dirfd, relpath, O_RDONLY);
+	if ( fd < 0 ) { error(0, errno, "%s", path); return false; }
+	struct stat st;
+	if ( fstat(fd, &st) ) { error(0, errno, "stat: %s", path); return false; }
+	if ( S_ISDIR(st.st_mode) )
+	{
+		if ( types & TYPE_DIR )
+			printf("%s\n", path);
+		DIR* dir = fdopendir(fd);
+		if ( !dir ) { perror("fdopendir"); close(fd); return false; }
+		struct dirent* entry;
+		while ( (entry = readdir(dir)) )
+		{
+			const char* name = entry->d_name;
+			if ( !strcmp(name, ".") || !strcmp(name, "..") )
+				continue;
+			char* newpath = AddElemToPath(path, name);
+			if ( !Find(fd, name, newpath, types) )
+			{
+				ret = false;
+				break;
+			}
+		}
+		closedir(dir);
+	}
+	else if ( S_ISREG(st.st_mode) )
+	{
+		if ( types & TYPE_FILE )
+			printf("%s\n", path);
+	}
+	return ret;
+}
+
+int main(int argc, char* argv[])
+{
+	const char* path = NULL;
+	bool found_options = false;
+	int types = 0;
+	for ( int i = 1; i < argc; i++ )
+	{
+		const char* arg = argv[i];
+		if ( arg[0] != '-' )
+		{
+			if ( found_options )
+				error(1, 0, "path `%s' must come before options");
+			if ( path )
+				error(1, 0, "multiple paths are not supported");
+			path = arg;
+		}
+		else if ( !strcmp(arg, "-type") )
+		{
+			if ( i + 1 == argc )
+				error(1, 0, "-type expects an argument");
+			arg = argv[++i];
+			if ( !strcmp(arg, "f") )
+				types |= TYPE_FILE;
+			else if ( !strcmp(arg, "d") )
+				types |= TYPE_DIR;
+			else
+				error(1, 0, "unknown `-type %s'", arg);
+		}
+		else
+			error(1, 0, "unknown option `%s'", arg);
+	}
+	if ( !path )
+		path = ".";
+	if ( !types )
+		types = TYPE_FILE | TYPE_DIR;
+	return Find(AT_FDCWD, path, path, types) ? 0 : 1;
+}