Merge branch 'pschdir' into overgrown

Makefile

@@ -32,7 +32,7 @@ RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
 CFLAGS += -I$(SYSEXITS)
 
 .PHONY: all
-all: dj false fop hru intcmp mm npc retval rpn scrut str strcmp swab true
+all: dj false fop hru intcmp mm npc pschdir retval rpn scrut str strcmp swab true
 
 # keep build/include until bindgen(1) has stdin support
 # https://github.com/rust-lang/rust-bindgen/issues/2703
@@ -122,6 +122,11 @@ npc: build/bin/npc
 build/bin/npc: src/npc.c build
 	$(CC) $(CFLAGAS) -o $@ src/npc.c
 
+.PHONY: pschdir
+pschdir: build/bin/pschdir
+build/bin/pschdir: src/pschdir.c build
+	$(CC) $(CFLAGS) -o $@ src/pschdir.c
+
 .PHONY: retval
 retval: build/bin/retval
 build/bin/retval: src/retval.rs build rustlibs

src/pschdir.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2024 DTB <trinity@trinity.moe>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Affero 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 Affero General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see https://www.gnu.org/licenses/.
+ */
+
+#include <errno.h> /* EACCESS, ELOOP, ENAMETOOLONG, ENOENT, ENOTDIR, errno */
+#include <stdio.h> /* fprintf(3), stderr */
+#include <string.h> /* strerror(3) */
+#include <sysexits.h> /* EX_OSERR, EX_NOPERM, EX_NOINPUT, EX_UNAVAILABLE,
+                       * EX_USAGE */
+#include <unistd.h> /* chdir(2) */
+
+char *program_name = "pschdir";
+
+int main(int argc, char *argv[]){
+	if (argc < 3) {
+		fprintf(stderr, "Usage: %s directory command [argument...]\n",
+			argv[0] == NULL ? program_name : argv[0]);
+		return EX_USAGE;
+	}
+
+	if(chdir(argv[1]) != 0){
+		fprintf(stderr, "%s: %s: %s\n", argv[0], argv[1], strerror(errno));
+
+		switch (errno) {
+			case ENAMETOOLONG:	return EX_OSERR;
+			case EACCES:      	return EX_NOPERM;
+			case ENOENT:
+			case ENOTDIR:     	return EX_NOINPUT;
+			default:          	return EX_UNAVAILABLE;
+		}
+	}
+
+	execvp(argv[2], &argv[2]);
+}