blob: c2250531419ec8d567100fc9767bcda86d9c3456
| 1 | /* |
| 2 | * rev implementation for busybox |
| 3 | * |
| 4 | * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com> |
| 5 | * |
| 6 | * Licensed under GPLv2, see file LICENSE in this source tree. |
| 7 | */ |
| 8 | //config:config REV |
| 9 | //config: bool "rev" |
| 10 | //config: default y |
| 11 | //config: help |
| 12 | //config: Reverse lines of a file or files. |
| 13 | |
| 14 | //applet:IF_REV(APPLET(rev, BB_DIR_BIN, BB_SUID_DROP)) |
| 15 | |
| 16 | //kbuild:lib-$(CONFIG_REV) += rev.o |
| 17 | |
| 18 | //usage:#define rev_trivial_usage |
| 19 | //usage: "[FILE]..." |
| 20 | //usage:#define rev_full_usage "\n\n" |
| 21 | //usage: "Reverse lines of FILE" |
| 22 | |
| 23 | #include "libbb.h" |
| 24 | #include "unicode.h" |
| 25 | |
| 26 | #undef CHAR_T |
| 27 | #if ENABLE_UNICODE_SUPPORT |
| 28 | # define CHAR_T wchar_t |
| 29 | #else |
| 30 | # define CHAR_T char |
| 31 | #endif |
| 32 | |
| 33 | /* In-place invert */ |
| 34 | static void strrev(CHAR_T *s, int len) |
| 35 | { |
| 36 | int i; |
| 37 | |
| 38 | if (len != 0) { |
| 39 | len--; |
| 40 | if (len != 0 && s[len] == '\n') |
| 41 | len--; |
| 42 | } |
| 43 | |
| 44 | for (i = 0; i < len; i++, len--) { |
| 45 | CHAR_T c = s[i]; |
| 46 | s[i] = s[len]; |
| 47 | s[len] = c; |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | int rev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 52 | int rev_main(int argc UNUSED_PARAM, char **argv) |
| 53 | { |
| 54 | int retval; |
| 55 | size_t bufsize; |
| 56 | char *buf; |
| 57 | |
| 58 | init_unicode(); |
| 59 | |
| 60 | getopt32(argv, ""); |
| 61 | argv += optind; |
| 62 | if (!argv[0]) |
| 63 | argv = (char **)&bb_argv_dash; |
| 64 | |
| 65 | retval = EXIT_SUCCESS; |
| 66 | bufsize = 256; |
| 67 | buf = xmalloc(bufsize); |
| 68 | do { |
| 69 | size_t pos; |
| 70 | FILE *fp; |
| 71 | |
| 72 | fp = fopen_or_warn_stdin(*argv++); |
| 73 | if (!fp) { |
| 74 | retval = EXIT_FAILURE; |
| 75 | continue; |
| 76 | } |
| 77 | |
| 78 | pos = 0; |
| 79 | while (1) { |
| 80 | /* Read one line */ |
| 81 | buf[bufsize - 1] = 1; /* not 0 */ |
| 82 | if (!fgets(buf + pos, bufsize - pos, fp)) |
| 83 | break; /* EOF/error */ |
| 84 | if (buf[bufsize - 1] == '\0' /* fgets filled entire buffer */ |
| 85 | && buf[bufsize - 2] != '\n' /* and did not read '\n' */ |
| 86 | && !feof(fp) |
| 87 | ) { |
| 88 | /* Line is too long, extend buffer */ |
| 89 | pos = bufsize - 1; |
| 90 | bufsize += 64 + bufsize / 8; |
| 91 | buf = xrealloc(buf, bufsize); |
| 92 | continue; |
| 93 | } |
| 94 | |
| 95 | /* Process and print it */ |
| 96 | #if ENABLE_UNICODE_SUPPORT |
| 97 | { |
| 98 | wchar_t *tmp = xmalloc(bufsize * sizeof(wchar_t)); |
| 99 | /* Convert to wchar_t (might error out!) */ |
| 100 | int len = mbstowcs(tmp, buf, bufsize); |
| 101 | if (len >= 0) { |
| 102 | strrev(tmp, len); |
| 103 | /* Convert back to char */ |
| 104 | wcstombs(buf, tmp, bufsize); |
| 105 | } |
| 106 | free(tmp); |
| 107 | } |
| 108 | #else |
| 109 | strrev(buf, strlen(buf)); |
| 110 | #endif |
| 111 | fputs(buf, stdout); |
| 112 | } |
| 113 | fclose(fp); |
| 114 | } while (*argv); |
| 115 | |
| 116 | if (ENABLE_FEATURE_CLEAN_UP) |
| 117 | free(buf); |
| 118 | |
| 119 | fflush_stdout_and_exit(retval); |
| 120 | } |
| 121 |