diff options
| -rw-r--r-- | coreutils/tac.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/coreutils/tac.c b/coreutils/tac.c new file mode 100644 index 0000000..6aa0528 --- /dev/null +++ b/coreutils/tac.c @@ -0,0 +1,68 @@ +/* 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! */ + +int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int tac_main(int argc, char **argv) +{ + char **name; + FILE *f; + char *line; + llist_t *list = NULL; + int retval = EXIT_SUCCESS; + + argv++; + if (!*argv) + *--argv = (char *)"-"; + /* We will read from last file to first */ + name = argv; + while (*name) + name++; + + do { + name--; + f = fopen_or_warn_stdin(*name); + if (f == NULL) { + retval = EXIT_FAILURE; + continue; + } + + errno = 0; + /* FIXME: NUL bytes are mishandled. */ + while ((line = xmalloc_fgets(f)) != NULL) + llist_add_to(&list, line); + + /* xmalloc_fgets uses getc and returns NULL on error or EOF. */ + /* It sets errno to ENOENT on EOF, but fopen_or_warn_stdin would */ + /* catch this error so we can filter it out here. */ + if (errno && errno != ENOENT) { + bb_simple_perror_msg(*name); + retval = EXIT_FAILURE; + } + } while (name != argv); + + while (list) { + printf("%s", list->data); + list = list->link; + } + + return retval; +} |