cat(1p), true(1p), false(1p): added source files & Makefile

Makefile

@@ -0,0 +1,28 @@
+# Copyright (c) 2023 YAC
+# SPDX-License-Identifier: FSFAP
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice and this
+# notice are preserved.  This file is offered as-is, without any warranty.
+
+.POSIX:
+
+PREFIX=/usr/local/bin
+
+build: build_dir cat false true
+
+cat: build_dir
+	cc -o build/cat src/cat.c
+
+false: build_dir
+	cc -o build/false src/false.c
+
+true: build_dir
+	cc -o build/true src/true.c
+
+build_dir:
+	mkdir -p build
+
+install: build
+	mkdir -p $(PREFIX)
+	cp -f build/* $(PREFIX)/

src/cat.c

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2023 YAC
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * This file is part of YAC coreutils.
+ *
+ * YAC coreutils 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.
+ * 
+ * YAC coreutils 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 <fcntl.h>
+#include <sysexits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+	int i = 1;
+	bool u = false;
+
+	char *usage_text = "(-u) [file...]";
+	int buf_size = strlen(argv[0]) + strlen("Usage: ") + strlen(usage_text) + 3;
+	char *usage = calloc(buf_size, buf_size);
+
+	if ((
+		snprintf(usage, buf_size, "Usage: %s (-u) [file...]\n", argv[0])
+	) < 0 ) {}
+
+	int opt;
+
+	while ((opt = getopt(argc, argv, "u")) != -1) {
+		switch(opt) {
+			/*
+			 * From cat(1p):
+			 *
+			 * -u        Write bytes from the input file to the standard output
+			 *           without delay as each is read.
+			 */
+			case 'u':
+				i = 2;
+				u = true;
+				break;
+			default:
+				break;
+		}
+	}
+
+	FILE *file;
+
+	for (; i <= (argc - 1); i++) {
+	  /*
+		 * From cat(1p):
+		 *
+		 * file      A pathname of an input file. If no file operands are
+		 *           specified, the standard input shall be used. If a file is
+		 *           '-', the cat utility shall read from the standard input at
+		 *           that point in the sequence. The cat utility shall not close
+		 *           and reopen standard input when it is referenced in this way,
+		 *           but shall accept multiple occurrences of '-' as a file
+		 *           operand.
+		 */
+		printf("argv[%d]: %s\n", i, argv[1]);
+
+		if (argc == 1 || argv[i] == "-") { file = fdopen(1, "r"); }
+		else if ((file = fopen(argv[i], O_RDONLY)) == NULL) {
+			fputs(usage, stderr); 
+			return EX_NOINPUT;
+		}
+
+		int byte = 0;
+
+		if (u) {
+			while (byte != EOF) {
+				byte = fgetc(file);
+				putchar(byte);
+			}
+		} else {
+			char *buf = calloc(4096, 1);
+		}
+		if (fclose(file) == -1) {
+			fprintf(stderr, "%s: %s: Error closing file.\n", argv[0], argv[i]);
+			return EX_OSERR;
+		}
+	}
+
+	return EX_OK;
+}

src/false.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023 YAC
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * This file is part of YAC coreutils.
+ *
+ * YAC coreutils 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.
+ * 
+ * YAC coreutils 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/.
+ */
+
+int main() { return 1; }

src/true.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023 YAC
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * This file is part of YAC coreutils.
+ *
+ * YAC coreutils 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.
+ * 
+ * YAC coreutils 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/.
+ */
+
+int main() {}