121 lines
2.3 KiB
C
121 lines
2.3 KiB
C
/*
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* rev implementation for busybox
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*
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* Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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//config:config REV
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//config: bool "rev (4.5 kb)"
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//config: default y
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//config: help
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//config: Reverse lines of a file or files.
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//applet:IF_REV(APPLET(rev, BB_DIR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_REV) += rev.o
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//usage:#define rev_trivial_usage
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//usage: "[FILE]..."
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//usage:#define rev_full_usage "\n\n"
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//usage: "Reverse lines of FILE"
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#include "libbb.h"
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#include "unicode.h"
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#undef CHAR_T
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#if ENABLE_UNICODE_SUPPORT
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# define CHAR_T wchar_t
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#else
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# define CHAR_T char
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#endif
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/* In-place invert */
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static void strrev(CHAR_T *s, int len)
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{
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int i;
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if (len != 0) {
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len--;
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if (len != 0 && s[len] == '\n')
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len--;
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}
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for (i = 0; i < len; i++, len--) {
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CHAR_T c = s[i];
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s[i] = s[len];
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s[len] = c;
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}
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}
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int rev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int rev_main(int argc UNUSED_PARAM, char **argv)
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{
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int retval;
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size_t bufsize;
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char *buf;
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init_unicode();
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getopt32(argv, "");
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argv += optind;
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if (!argv[0])
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argv = (char **)&bb_argv_dash;
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retval = EXIT_SUCCESS;
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bufsize = 256;
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buf = xmalloc(bufsize);
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do {
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size_t pos;
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FILE *fp;
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fp = fopen_or_warn_stdin(*argv++);
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if (!fp) {
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retval = EXIT_FAILURE;
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continue;
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}
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pos = 0;
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while (1) {
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/* Read one line */
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buf[bufsize - 1] = 1; /* not 0 */
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if (!fgets(buf + pos, bufsize - pos, fp))
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break; /* EOF/error */
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if (buf[bufsize - 1] == '\0' /* fgets filled entire buffer */
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&& buf[bufsize - 2] != '\n' /* and did not read '\n' */
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&& !feof(fp)
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) {
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/* Line is too long, extend buffer */
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pos = bufsize - 1;
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bufsize += 64 + bufsize / 8;
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buf = xrealloc(buf, bufsize);
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continue;
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}
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/* Process and print it */
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#if ENABLE_UNICODE_SUPPORT
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{
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wchar_t *tmp = xmalloc(bufsize * sizeof(wchar_t));
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/* Convert to wchar_t (might error out!) */
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int len = mbstowcs(tmp, buf, bufsize);
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if (len >= 0) {
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strrev(tmp, len);
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/* Convert back to char */
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wcstombs(buf, tmp, bufsize);
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}
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free(tmp);
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}
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#else
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strrev(buf, strlen(buf));
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#endif
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fputs(buf, stdout);
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}
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fclose(fp);
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} while (*argv);
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if (ENABLE_FEATURE_CLEAN_UP)
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free(buf);
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fflush_stdout_and_exit(retval);
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}
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