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