2 * rev implementation for busybox
4 * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
6 * Licensed under GPLv2, see file LICENSE in this source tree.
9 //applet:IF_REV(APPLET(rev, BB_DIR_BIN, BB_SUID_DROP))
11 //kbuild:lib-$(CONFIG_REV) += rev.o
17 //config: Reverse lines of a file or files.
19 //usage:#define rev_trivial_usage
21 //usage:#define rev_full_usage "\n\n"
22 //usage: "Reverse lines of FILE"
28 #if ENABLE_UNICODE_SUPPORT
29 # define CHAR_T wchar_t
35 static void strrev(CHAR_T *s, int len)
41 if (len != 0 && s[len] == '\n')
45 for (i = 0; i < len; i++, len--) {
52 int rev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
53 int rev_main(int argc UNUSED_PARAM, char **argv)
64 argv = (char **)&bb_argv_dash;
66 retval = EXIT_SUCCESS;
68 buf = xmalloc(bufsize);
73 fp = fopen_or_warn_stdin(*argv++);
75 retval = EXIT_FAILURE;
82 buf[bufsize - 1] = 1; /* not 0 */
83 if (!fgets(buf + pos, bufsize - pos, fp))
84 break; /* EOF/error */
85 if (buf[bufsize - 1] == '\0' /* fgets filled entire buffer */
86 && buf[bufsize - 2] != '\n' /* and did not read '\n' */
89 /* Line is too long, extend buffer */
91 bufsize += 64 + bufsize / 8;
92 buf = xrealloc(buf, bufsize);
96 /* Process and print it */
97 #if ENABLE_UNICODE_SUPPORT
99 wchar_t *tmp = xmalloc(bufsize * sizeof(wchar_t));
100 /* Convert to wchar_t (might error out!) */
101 int len = mbstowcs(tmp, buf, bufsize);
104 /* Convert back to char */
105 wcstombs(buf, tmp, bufsize);
110 strrev(buf, strlen(buf));
117 if (ENABLE_FEATURE_CLEAN_UP)
120 fflush_stdout_and_exit(retval);