Florian Fischer
80 lines
2.3 KiB
C
80 lines
2.3 KiB
C
/// @file cat.c
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/// @brief `cat` program.
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/// @copyright (c) 2014-2024 This file is distributed under the MIT License.
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/// See LICENSE.md for details.
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#include "io/debug.h"
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#include "stddef.h"
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#include <fcntl.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/unistd.h>
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#include <strerror.h>
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#include <sys/stat.h>
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static inline void print_content(const char *path, char *buffer, unsigned buflen)
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{
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pr_warning("Printing content of %s\n", path);
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// Open the file.
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int fd = open(path, O_RDONLY, 42);
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if (fd >= 0) {
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ssize_t bytes_read = 0;
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// Put on the standard output the characters.
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while ((bytes_read = read(fd, buffer, buflen)) > 0) {
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write(STDOUT_FILENO, buffer, bytes_read);
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}
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// Close the file descriptor.
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close(fd);
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} else {
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printf("cat: %s: %s\n\n", path, strerror(errno));
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}
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}
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int main(int argc, char **argv)
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{
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if (argc < 2) {
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printf("cat: missing operand.\n");
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printf("Try 'cat --help' for more information.\n\n");
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return 1;
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}
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// Check if `--help` is provided.
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for (int i = 1; i < argc; ++i) {
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if ((strcmp(argv[i], "--help") == 0) || (strcmp(argv[i], "-h") == 0)) {
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printf("Prints the content of the given file.\n");
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printf("Usage:\n");
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printf(" cat <file>\n\n");
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return 0;
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}
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}
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int status = 0;
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// Prepare the buffer for reading.
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char buffer[BUFSIZ];
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// Iterate the arguments.
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for (int i = 1; i < argc; ++i) {
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stat_t statbuf;
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if (stat(argv[i], &statbuf) == -1) {
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printf("cat: %s: %s\n\n", argv[i], strerror(errno));
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continue;
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}
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// If it is a regular file, just print the content.
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if (S_ISREG(statbuf.st_mode)) {
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print_content(argv[i], buffer, BUFSIZ);
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} else if (S_ISDIR(statbuf.st_mode)) {
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printf("cat: %s: Is a directory\n\n", argv[i]);
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status = 1;
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} else if (S_ISLNK(statbuf.st_mode)) {
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if (readlink(argv[i], buffer, BUFSIZ)) {
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print_content(buffer, buffer, BUFSIZ);
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} else {
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printf("cat: %s: %s\n\n", argv[i], strerror(errno));
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status = 1;
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}
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}
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}
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putchar('\n');
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putchar('\n');
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return status;
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}
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