linux下的wc命令的源代码

/* wc - print the number of lines, words, and bytes in filesCopyright (C) 1985, 1991, 1995-2010 Free Software Foundation, Inc.This program is free software: you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation, either version 3 of the License, or(at your option) any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program. If not, see </licenses/>. */ /* Written by Paul Rubin, phr@and David MacKenzie, djm@. */#include <config.h>#include <stdio.h>#include <assert.h>#include <getopt.h>#include <sys/types.h>#include <wchar.h>#include <wctype.h>#include "system.h"#include "argv-iter.h"#include "error.h"#include "mbchar.h"#include "physmem.h"#include "quote.h"#include "quotearg.h"#include "readtokens0.h"#include "safe-read.h"#include "xfreopen.h"#if !defined iswspace && !HAVE_ISWSPACE# define iswspace(wc) \((wc) == to_uchar (wc) && isspace (to_uchar (wc)))#endif/* The official name of this program (e.g., no `g' prefix). */#define PROGRAM_NAME "wc"#define AUTHORS \proper_name ("Paul Rubin"), \proper_name ("David MacKenzie")/* Size of atomic reads. */#define BUFFER_SIZE (16 * 1024)/* Cumulative number of lines, words, chars and bytes in all files so far.max_line_length is the maximum over all files processed so far. */ static uintmax_t total_lines;static uintmax_t total_words;static uintmax_t total_chars;static uintmax_t total_bytes;static uintmax_t max_line_length;/* Which counts to print. */static bool print_lines, print_words, print_chars, print_bytes;static bool print_linelength;/* The print width of each count. */static int number_width;/* True if we have ever read the standard input. */static bool have_read_stdin;/* The result of calling fstat or stat on a file descriptor or file. */struct fstatus{/* If positive, fstat or stat has not been called yet. Otherwise, this is the value returned from fstat or stat. */int failed;/* If FAILED is zero, this is the file's status. */struct stat st;};/* For long options that have no equivalent short option, use a non-character as a pseudo short option, starting with CHAR_MAX + 1. */ enum{FILES0_FROM_OPTION = CHAR_MAX + 1};static struct option const longopts[] ={{"bytes", no_argument, NULL, 'c'},{"chars", no_argument, NULL, 'm'},{"lines", no_argument, NULL, 'l'},{"words", no_argument, NULL, 'w'},{"files0-from", required_argument, NULL, FILES0_FROM_OPTION}, {"max-line-length", no_argument, NULL, 'L'},{GETOPT_HELP_OPTION_DECL},{GETOPT_VERSION_OPTION_DECL},{NULL, 0, NULL, 0}};voidusage (int status){if (status != EXIT_SUCCESS)fprintf (stderr, _("Try `%s --help' for more information.\n"),program_name);else{printf (_("\Usage: %s [OPTION]... [FILE]...\n\or: %s [OPTION]... --files0-from=F\n\"),program_name, program_name);fputs (_("\Print newline, word, and byte counts for each FILE, and a total line if\n\more than one FILE is specified. With no FILE, or when FILE is -,\n\read standard input.\n\-c, --bytes print the byte counts\n\-m, --chars print the character counts\n\-l, --lines print the newline counts\n\"), stdout);fputs (_("\--files0-from=F read input from the files specified by\n\NUL-terminated names in file F;\n\If F is - then read names from standard input\n\ -L, --max-line-length print the length of the longest line\n\-w, --words print the word counts\n\"), stdout);fputs (HELP_OPTION_DESCRIPTION, stdout);fputs (VERSION_OPTION_DESCRIPTION, stdout);emit_ancillary_info ();}exit (status);}/* FILE is the name of the file (or NULL for standard input)associated with the specified counters. */static voidwrite_counts (uintmax_t lines,uintmax_t words,uintmax_t chars,uintmax_t bytes,uintmax_t linelength,const char *file){static char const format_sp_int[] = " %*s";char const *format_int = format_sp_int + 1;char buf[INT_BUFSIZE_BOUND (uintmax_t)];if (print_lines){printf (format_int, number_width, umaxtostr (lines, buf));format_int = format_sp_int;}if (print_words){printf (format_int, number_width, umaxtostr (words, buf));format_int = format_sp_int;}if (print_chars){printf (format_int, number_width, umaxtostr (chars, buf));format_int = format_sp_int;}if (print_bytes){printf (format_int, number_width, umaxtostr (bytes, buf));format_int = format_sp_int;}if (print_linelength){printf (format_int, number_width, umaxtostr (linelength, buf));}if (file)printf (" %s", file);putchar ('\n');}/* Count words. FILE_X is the name of the file (or NULL for standard input) that is open on descriptor FD. *FSTATUS is its status.Return true if successful. */static boolwc (int fd, char const *file_x, struct fstatus *fstatus){bool ok = true;char buf[BUFFER_SIZE + 1];size_t bytes_read;uintmax_t lines, words, chars, bytes, linelength;bool count_bytes, count_chars, count_complicated;char const *file = file_x ? file_x : _("standard input");lines = words = chars = bytes = linelength = 0;/* If in the current locale, chars are equivalent to bytes, we prefer counting bytes, because that's easier. */#if MB_LEN_MAX > 1if (MB_CUR_MAX > 1){count_bytes = print_bytes;count_chars = print_chars;}else#endif{count_bytes = print_bytes || print_chars;count_chars = false;}count_complicated = print_words || print_linelength;/* When counting only bytes, save some line- and word-counting overhead. If FD is a `regular' Unix file, using lseek is enoughto get its `size' in bytes. Otherwise, read blocks of BUFFER_SIZEbytes at a time until EOF. Note that the `size' (number of bytes)that wc reports is smaller than stats.st_size when the file is notpositioned at its beginning. That's why the lseek calls below arenecessary. For example the command`(dd ibs=99k skip=1 count=0; ./wc -c) < /etc/group'should make wc report `0' bytes. */if (count_bytes && !count_chars && !print_lines && !count_complicated) {off_t current_pos, end_pos;if (0 < fstatus->failed)fstatus->failed = fstat (fd, &fstatus->st);if (! fstatus->failed && S_ISREG (fstatus->st.st_mode)&& (current_pos = lseek (fd, (off_t) 0, SEEK_CUR)) != -1&& (end_pos = lseek (fd, (off_t) 0, SEEK_END)) != -1){/* Be careful here. The current position may actually bebeyond the end of the file. As in the example above. */ bytes = end_pos < current_pos ? 0 : end_pos - current_pos;}else{while ((bytes_read = safe_read (fd, buf, BUFFER_SIZE)) > 0){if (bytes_read == SAFE_READ_ERROR){error (0, errno, "%s", file);ok = false;break;}bytes += bytes_read;}}}else if (!count_chars && !count_complicated){/* Use a separate loop when counting only lines or lines and bytes -- but not chars or words. */while ((bytes_read = safe_read (fd, buf, BUFFER_SIZE)) > 0){char *p = buf;if (bytes_read == SAFE_READ_ERROR){error (0, errno, "%s", file);ok = false;break;}while ((p = memchr (p, '\n', (buf + bytes_read) - p))){++p;++lines;}bytes += bytes_read;}}#if MB_LEN_MAX > 1# define SUPPORT_OLD_MBRTOWC 1else if (MB_CUR_MAX > 1){bool in_word = false;uintmax_t linepos = 0;DECLARE_ZEROED_AGGREGATE (mbstate_t, state);bool in_shift = false;# if SUPPORT_OLD_MBRTOWC/* Back-up the state before each multibyte character conversion and move the last incomplete character of the buffer to the frontof the buffer. This is needed because we don't know whetherthe `mbrtowc' function updates the state when it returns -2, -this is the ISO C 99 and glibc-2.2 behaviour - or not - amendedANSI C, glibc-2.1 and Solaris 5.7 behaviour. We don't have anautoconf test for this, yet. */size_t prev = 0; /* number of bytes carried over from previous round */ # elseconst size_t prev = 0;# endifwhile ((bytes_read = safe_read (fd, buf + prev, BUFFER_SIZE - prev)) > 0){const char *p;# if SUPPORT_OLD_MBRTOWCmbstate_t backup_state;# endifif (bytes_read == SAFE_READ_ERROR){error (0, errno, "%s", file);ok = false;break;}bytes += bytes_read;p = buf;bytes_read += prev;do{wchar_t wide_char;size_t n;if (!in_shift && is_basic (*p)){/* Handle most ASCII characters quickly, without callingmbrtowc(). */n = 1;wide_char = *p;}else{in_shift = true;# if SUPPORT_OLD_MBRTOWCbackup_state = state;# endifn = mbrtowc (&wide_char, p, bytes_read, &state);if (n == (size_t) -2){# if SUPPORT_OLD_MBRTOWCstate = backup_state;# endifbreak;}if (n == (size_t) -1){/* Remember that we read a byte, but don't complainabout the error. Because of the decoding error,this is a considered to be byte but not acharacter (that is, chars is not incremented). */p++;bytes_read--;continue;}if (mbsinit (&state))in_shift = false;if (n == 0){wide_char = 0;n = 1;}}p += n;bytes_read -= n;chars++;switch (wide_char){case '\n':lines++;/* Fall through. */case '\r':case '\f':if (linepos > linelength)linelength = linepos;linepos = 0;goto mb_word_separator;case '\t':linepos += 8 - (linepos % 8);goto mb_word_separator;case ' ':linepos++;/* Fall through. */case '\v':mb_word_separator:words += in_word;in_word = false;break;default:if (iswprint (wide_char)){int width = wcwidth (wide_char);if (width > 0)linepos += width;if (iswspace (wide_char))goto mb_word_separator;in_word = true;}break;}}while (bytes_read > 0);# if SUPPORT_OLD_MBRTOWCif (bytes_read > 0){if (bytes_read == BUFFER_SIZE){/* Encountered a very long redundant shift sequence. */p++;bytes_read--;}memmove (buf, p, bytes_read);}prev = bytes_read;# endif}if (linepos > linelength)linelength = linepos;words += in_word;}#endifelse{bool in_word = false;uintmax_t linepos = 0;while ((bytes_read = safe_read (fd, buf, BUFFER_SIZE)) > 0) {const char *p = buf;if (bytes_read == SAFE_READ_ERROR){error (0, errno, "%s", file);ok = false;break;}bytes += bytes_read;do{switch (*p++){case '\n':lines++;/* Fall through. */case '\r':case '\f':if (linepos > linelength)linelength = linepos;linepos = 0;goto word_separator;case '\t':linepos += 8 - (linepos % 8);goto word_separator;case ' ':linepos++;/* Fall through. */case '\v':word_separator:words += in_word;in_word = false;break;default:if (isprint (to_uchar (p[-1]))){linepos++;if (isspace (to_uchar (p[-1])))goto word_separator;in_word = true;}break;}}while (--bytes_read);}if (linepos > linelength)linelength = linepos;words += in_word;}if (count_chars < print_chars)chars = bytes;write_counts (lines, words, chars, bytes, linelength, file_x); total_lines += lines;total_words += words;total_chars += chars;total_bytes += bytes;if (linelength > max_line_length)max_line_length = linelength;return ok;}static boolwc_file (char const *file, struct fstatus *fstatus){if (! file || STREQ (file, "-")){have_read_stdin = true;if (O_BINARY && ! isatty (STDIN_FILENO))xfreopen (NULL, "rb", stdin);return wc (STDIN_FILENO, file, fstatus);}else{int fd = open (file, O_RDONLY | O_BINARY);if (fd == -1){error (0, errno, "%s", file);return false;}else{bool ok = wc (fd, file, fstatus);if (close (fd) != 0){error (0, errno, "%s", file);return false;}return ok;}}}/* Return the file status for the NFILES files addressed by FILE.Optimize the case where only one number is printed, for just onefile; in that case we can use a print width of 1, so we don't needto stat the file. Handle the case of (nfiles == 0) in the same way;that happens when we don't know how long the list of file names will be. */ static struct fstatus *get_input_fstatus (int nfiles, char *const *file){struct fstatus *fstatus = xnmalloc (nfiles ? nfiles : 1, sizeof *fstatus);if (nfiles == 0|| (nfiles == 1&& ((print_lines + print_words + print_chars+ print_bytes + print_linelength)== 1)))fstatus[0].failed = 1;else{int i;for (i = 0; i < nfiles; i++)fstatus[i].failed = (! file[i] || STREQ (file[i], "-")? fstat (STDIN_FILENO, &fstatus[i].st): stat (file[i], &fstatus[i].st));}return fstatus;}/* Return a print width suitable for the NFILES files whose status is recorded in FSTATUS. Optimize the same special case thatget_input_fstatus optimizes. */static intcompute_number_width (int nfiles, struct fstatus const *fstatus) {int width = 1;if (0 < nfiles && fstatus[0].failed <= 0){int minimum_width = 1;uintmax_t regular_total = 0;int i;for (i = 0; i < nfiles; i++)if (! fstatus[i].failed){if (S_ISREG (fstatus[i].st.st_mode))regular_total += fstatus[i].st.st_size;elseminimum_width = 7;}for (; 10 <= regular_total; regular_total /= 10)width++;if (width < minimum_width)width = minimum_width;}return width;}intmain (int argc, char **argv){bool ok;int optc;int nfiles;char **files;char *files_from = NULL;struct fstatus *fstatus;struct Tokens tok;initialize_main (&argc, &argv);set_program_name (argv[0]);setlocale (LC_ALL, "");bindtextdomain (PACKAGE, LOCALEDIR);textdomain (PACKAGE);atexit (close_stdout);/* Line buffer stdout to ensure lines are written atomically and immediately so that processes running in parallel do not intersperse their output. */ setvbuf (stdout, NULL, _IOLBF, 0);print_lines = print_words = print_chars = print_bytes = false;print_linelength = false;total_lines = total_words = total_chars = total_bytes = max_line_length = 0; while ((optc = getopt_long (argc, argv, "clLmw", longopts, NULL)) != -1) switch (optc){case 'c':print_bytes = true;break;case 'm':print_chars = true;break;case 'l':print_lines = true;break;case 'w':print_words = true;break;case 'L':print_linelength = true;break;case FILES0_FROM_OPTION:files_from = optarg;break;case_GETOPT_HELP_CHAR;case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);default:usage (EXIT_FAILURE);}if (! (print_lines || print_words || print_chars || print_bytes|| print_linelength))print_lines = print_words = print_bytes = true;bool read_tokens = false;struct argv_iterator *ai;if (files_from){FILE *stream;/* When using --files0-from=F, you may not specify any fileson the command-line. */if (optind < argc){error (0, 0, _("extra operand %s"), quote (argv[optind]));fprintf (stderr, "%s\n",_("file operands cannot be combined with --files0-from"));usage (EXIT_FAILURE);}if (STREQ (files_from, "-"))stream = stdin;else{stream = fopen (files_from, "r");if (stream == NULL)error (EXIT_FAILURE, errno, _("cannot open %s for reading"),quote (files_from));}/* Read the file list into RAM if we can detect its size and thatsize is reasonable. Otherwise, we'll read a name at a time. */ struct stat st;if (fstat (fileno (stream), &st) == 0&& S_ISREG (st.st_mode)&& st.st_size <= MIN (10 * 1024 * 1024, physmem_available () / 2)){read_tokens = true;readtokens0_init (&tok);if (! readtokens0 (stream, &tok) || fclose (stream) != 0)error (EXIT_FAILURE, 0, _("cannot read file names from %s"),quote (files_from));files = tok.tok;nfiles = tok.n_tok;ai = argv_iter_init_argv (files);}else{files = NULL;nfiles = 0;ai = argv_iter_init_stream (stream);}}else{static char *stdin_only[] = { NULL };files = (optind < argc ? argv + optind : stdin_only);nfiles = (optind < argc ? argc - optind : 1);ai = argv_iter_init_argv (files);}fstatus = get_input_fstatus (nfiles, files);number_width = compute_number_width (nfiles, fstatus);int i;ok = true;for (i = 0; /* */; i++){bool skip_file = false;enum argv_iter_err ai_err;char *file_name = argv_iter (ai, &ai_err);if (ai_err == AI_ERR_EOF)break;if (!file_name){switch (ai_err){case AI_ERR_READ:error (0, errno, _("%s: read error"), quote (files_from));skip_file = true;continue;case AI_ERR_MEM:xalloc_die ();default:assert (!"unexpected error code from argv_iter");}}if (files_from && STREQ (files_from, "-") && STREQ (file_name, "-")){/* Give a better diagnostic in an unusual case:printf - | wc --files0-from=- */error (0, 0, _("when reading file names from stdin, ""no file name of %s allowed"),quote (file_name));skip_file = true;}if (!file_name[0]){/* Diagnose a zero-length file name. When it's oneamong many, knowing the record number may help.FIXME: currently print the record number only with--files0-from=FILE. Maybe do it for argv, too? */if (files_from == NULL)error (0, 0, "%s", _("invalid zero-length file name"));else{/* Using the standard `filename:line-number:' prefix here isnot totally appropriate, since NUL is the separator, not NL,but it might be better than nothing. */unsigned long int file_number = argv_iter_n_args (ai);error (0, 0, "%s:%lu: %s", quotearg_colon (files_from),file_number, _("invalid zero-length file name"));}skip_file = true;}if (skip_file)ok = false;elseok &= wc_file (file_name, &fstatus[nfiles ? i : 0]);}/* No arguments on the command line is fine. That means read from stdin.However, no arguments on the --files0-from input stream is an error means don't read anything. */if (ok && !files_from && argv_iter_n_args (ai) == 0)ok &= wc_file (NULL, &fstatus[0]);if (read_tokens)readtokens0_free (&tok);if (1 < argv_iter_n_args (ai))write_counts (total_lines, total_words, total_chars, total_bytes,max_line_length, _("total"));argv_iter_free (ai);free (fstatus);if (have_read_stdin && close (STDIN_FILENO) != 0)error (EXIT_FAILURE, errno, "-");exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);}。