Merge branch 'cat'

Makefile

@@ -0,0 +1,32 @@
+# Copyright (c) 2023 Emma Tebibyte
+# 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
+CFLAGS=-O3 -s -Wl,-z,noseparate-code,-z,nosectionheader -flto
+
+build: build_dir cat false true
+
+clean: build_dir
+	rm -rf build/
+
+cat: build_dir
+	cc $(CFLAGS) -o build/cat src/cat.c
+
+false: build_dir
+	cc $(CFLAGS) -o build/false src/false.c
+
+true: build_dir
+	cc $(CFLAGS) -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 +1,148 @@
+/*
+ * Copyright (c) 2023 Emma Tebibyte
+ * 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 <errno.h>
+#include <sysexits.h>
+#include <sys/stat.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <unistd.h>
+
+void cat(FILE *file, bool u) {
+	int byte = 0; /* variable for storing bytes as they are read */
+	int p = 0; /* index counter for bytes in buffered reading */
+	char buf[4096]; /* buffer for buffered reading */
+
+	if (u) {
+		while (byte != EOF) {
+			byte = fgetc(file);
+			putchar(byte);
+		}
+	} else {
+		while (byte != EOF) {
+			byte = fgetc(file);
+			if (p > sizeof(buf)) {
+				fputs(buf, stdout);
+				p = 0;
+			} else {
+				buf[p] = byte;
+				p += 1;
+			}
+		}
+
+		fwrite(buf, 1, p, stdout);
+		fflush(stdout);
+	}
+}
+
+int main(int argc, char *argv[]) {
+	bool u = false;
+	int opt;
+	int i;
+
+	extern int optind;
+	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':
+				u = true;
+				break;
+			default:
+				fprintf(stderr, "Usage: %s (-u) file...\n", argv[0]);
+				return EX_USAGE;
+		}
+	}
+
+	/*
+	 * 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.
+	 */
+
+	if (optind == argc) {
+		cat(stdin, u);
+		return 0;
+	}
+	
+	FILE *file;
+	struct stat stats;
+
+	for (i = optind; i < argc; i++) {
+		if (argv[i][0] == '-') {
+			switch (argv[i][1]) {
+				case '\0':
+					file = stdin;
+					break;
+				default:
+					continue;
+			}
+		} else if (stat(argv[i], &stats) == 0 && S_ISDIR(stats.st_mode)) {
+			fprintf(stderr, "%s: %s: Is a directory.\n", argv[0], argv[i]);
+			return EX_NOINPUT;
+		} else if ((file = fopen(argv[i], "r")) == NULL) {
+			switch (errno) {
+				case EACCES:
+					fprintf(stderr, "%s: %s: Permission denied.\n", argv[0], argv[i]);
+					return EX_NOINPUT;
+				case EISDIR:
+					fprintf(stderr, "%s: %s: Is a directory.\n", argv[0], argv[i]);
+					return EX_NOINPUT;
+				case ELOOP:
+					fprintf(
+						stderr,
+						"%s: %s: Is a symbolic link loop.\n",
+						argv[0],
+						argv[i]
+					);
+					return EX_UNAVAILABLE;
+				case EMFILE:
+					fprintf(stderr, "%s: Internal error.\n", argv[0]);
+					return EX_SOFTWARE;
+				case ENOENT: case ENOTDIR: case ENXIO:
+					fprintf(
+						stderr,
+						"%s: %s: No such file or directory.\n",
+						argv[0],
+						argv[i]
+					);
+					return EX_NOINPUT;
+				default:
+					fprintf(stderr, "%s: Unknown error.\n", argv[0]);
+					return EX_UNAVAILABLE;
+			}
+		}
+
+		cat(file, u);
+		if (file != stdin) { fclose(file); }
+	}
+
+	return EX_OK;
+}

src/false.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023 Emma Tebibyte
+ * 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 Emma Tebibyte
+ * 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() {}