| /* vi: set sw=4 ts=4: */ |
| /* |
| * tac implementation for busybox |
| * |
| * Copyright (C) 2003 Yang Xiaopeng <yxp at hanwang.com.cn> |
| * Copyright (C) 2007 Natanael Copa <natanael.copa@gmail.com> |
| * Copyright (C) 2007 Tito Ragusa <farmatito@tiscali.it> |
| * |
| * Licensed under GPLv2, see file License in this tarball for details. |
| * |
| */ |
| |
| /* tac - concatenate and print files in reverse */ |
| |
| /* Based on Yang Xiaopeng's (yxp at hanwang.com.cn) patch |
| * http://www.uclibc.org/lists/busybox/2003-July/008813.html |
| */ |
| |
| #include "libbb.h" |
| |
| /* This is a NOEXEC applet. Be very careful! */ |
| |
| struct lstring { |
| int size; |
| char buf[1]; |
| }; |
| |
| int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int tac_main(int argc UNUSED_PARAM, char **argv) |
| { |
| char **name; |
| FILE *f; |
| struct lstring *line = NULL; |
| llist_t *list = NULL; |
| int retval = EXIT_SUCCESS; |
| |
| #if ENABLE_DESKTOP |
| /* tac from coreutils 6.9 supports: |
| -b, --before |
| attach the separator before instead of after |
| -r, --regex |
| interpret the separator as a regular expression |
| -s, --separator=STRING |
| use STRING as the separator instead of newline |
| We support none, but at least we will complain or handle "--": |
| */ |
| getopt32(argv, ""); |
| argv += optind; |
| #else |
| argv++; |
| #endif |
| if (!*argv) |
| *--argv = (char *)"-"; |
| /* We will read from last file to first */ |
| name = argv; |
| while (*name) |
| name++; |
| |
| do { |
| int ch, i; |
| |
| name--; |
| f = fopen_or_warn_stdin(*name); |
| if (f == NULL) { |
| /* error message is printed by fopen_or_warn_stdin */ |
| retval = EXIT_FAILURE; |
| continue; |
| } |
| |
| errno = i = 0; |
| do { |
| ch = fgetc(f); |
| if (ch != EOF) { |
| if (!(i & 0x7f)) |
| /* Grow on every 128th char */ |
| line = xrealloc(line, i + 0x7f + sizeof(int) + 1); |
| line->buf[i++] = ch; |
| } |
| if (ch == '\n' || (ch == EOF && i != 0)) { |
| line = xrealloc(line, i + sizeof(int)); |
| line->size = i; |
| llist_add_to(&list, line); |
| line = NULL; |
| i = 0; |
| } |
| } while (ch != EOF); |
| /* fgetc sets errno to ENOENT on EOF, we don't want |
| * to warn on this non-error! */ |
| if (errno && errno != ENOENT) { |
| bb_simple_perror_msg(*name); |
| retval = EXIT_FAILURE; |
| } |
| } while (name != argv); |
| |
| while (list) { |
| line = (struct lstring *)list->data; |
| xwrite(STDOUT_FILENO, line->buf, line->size); |
| if (ENABLE_FEATURE_CLEAN_UP) { |
| free(llist_pop(&list)); |
| } else { |
| list = list->link; |
| } |
| } |
| |
| return retval; |
| } |