/* vi: set sw=4 ts=4: */
/*
 * wc implementation for busybox
 *
 * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- option -m is not currently supported. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/wc.html */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Rewritten to fix a number of problems and do some size optimizations.
 * Problems in the previous busybox implementation (besides bloat) included:
 *  1) broken 'wc -c' optimization (read note below)
 *  2) broken handling of '-' args
 *  3) no checking of ferror on EOF returns
 *  4) isprint() wasn't considered when word counting.
 *
 * TODO:
 *
 * When locale support is enabled, count multibyte chars in the '-m' case.
 *
 * NOTES:
 *
 * The previous busybox wc attempted an optimization using stat for the
 * case of counting chars only.  I omitted that because it was broken.
 * It didn't take into account the possibility of input coming from a
 * pipe, or input from a file with file pointer not at the beginning.
 *
 * To implement such a speed optimization correctly, not only do you
 * need the size, but also the file position.  Note also that the
 * file position may be past the end of file.  Consider the example
 * (adapted from example in gnu wc.c)
 *
 *      echo hello > /tmp/testfile &&
 *      (dd ibs=1k skip=1 count=0 &> /dev/null; wc -c) < /tmp/testfile
 *
 * for which 'wc -c' should output '0'.
 */

#include "libbb.h"

#if ENABLE_LOCALE_SUPPORT
#define isspace_given_isprint(c) isspace(c)
#else
#undef isspace
#undef isprint
#define isspace(c) ((((c) == ' ') || (((unsigned int)((c) - 9)) <= (13 - 9))))
#define isprint(c) (((unsigned int)((c) - 0x20)) <= (0x7e - 0x20))
#define isspace_given_isprint(c) ((c) == ' ')
#endif

#if ENABLE_FEATURE_WC_LARGE
#define COUNT_T unsigned long long
#define COUNT_FMT "llu"
#else
#define COUNT_T unsigned
#define COUNT_FMT "u"
#endif

enum {
        WC_LINES        = 0,
        WC_WORDS        = 1,
        WC_CHARS        = 2,
        WC_LENGTH       = 3
};

int wc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int wc_main(int argc UNUSED_PARAM, char **argv)
{
        FILE *fp;
        const char *s, *arg;
        const char *start_fmt = " %9"COUNT_FMT + 1;
        const char *fname_fmt = " %s\n";
        COUNT_T *pcounts;
        COUNT_T counts[4];
        COUNT_T totals[4];
        unsigned linepos;
        unsigned u;
        int num_files = 0;
        int c;
        smallint status = EXIT_SUCCESS;
        smallint in_word;
        unsigned print_type;

        print_type = getopt32(argv, "lwcL");

        if (print_type == 0) {
                print_type = (1 << WC_LINES) | (1 << WC_WORDS) | (1 << WC_CHARS);
        }

        argv += optind;
        if (!argv[0]) {
                *--argv = (char *) bb_msg_standard_input;
                fname_fmt = "\n";
                if (!((print_type-1) & print_type)) /* exactly one option? */
                        start_fmt = "%"COUNT_FMT;
        }

        memset(totals, 0, sizeof(totals));

        pcounts = counts;

        while ((arg = *argv++) != 0) {
                ++num_files;
                fp = fopen_or_warn_stdin(arg);
                if (!fp) {
                        status = EXIT_FAILURE;
                        continue;
                }

                memset(counts, 0, sizeof(counts));
                linepos = 0;
                in_word = 0;

                do {
                        /* Our -w doesn't match GNU wc exactly... oh well */

                        ++counts[WC_CHARS];
                        c = getc(fp);
                        if (isprint(c)) {
                                ++linepos;
                                if (!isspace_given_isprint(c)) {
                                        in_word = 1;
                                        continue;
                                }
                        } else if (((unsigned int)(c - 9)) <= 4) {
                                /* \t  9
                                 * \n 10
                                 * \v 11
                                 * \f 12
                                 * \r 13
                                 */
                                if (c == '\t') {
                                        linepos = (linepos | 7) + 1;
                                } else {                        /* '\n', '\r', '\f', or '\v' */
                                DO_EOF:
                                        if (linepos > counts[WC_LENGTH]) {
                                                counts[WC_LENGTH] = linepos;
                                        }
                                        if (c == '\n') {
                                                ++counts[WC_LINES];
                                        }
                                        if (c != '\v') {
                                                linepos = 0;
                                        }
                                }
                        } else if (c == EOF) {
                                if (ferror(fp)) {
                                        bb_simple_perror_msg(arg);
                                        status = EXIT_FAILURE;
                                }
                                --counts[WC_CHARS];
                                goto DO_EOF;            /* Treat an EOF as '\r'. */
                        } else {
                                continue;
                        }

                        counts[WC_WORDS] += in_word;
                        in_word = 0;
                        if (c == EOF) {
                                break;
                        }
                } while (1);

                if (totals[WC_LENGTH] < counts[WC_LENGTH]) {
                        totals[WC_LENGTH] = counts[WC_LENGTH];
                }
                totals[WC_LENGTH] -= counts[WC_LENGTH];

                fclose_if_not_stdin(fp);

        OUTPUT:
                /* coreutils wc tries hard to print pretty columns
                 * (saves results for all files, find max col len etc...)
                 * we won't try that hard, it will bloat us too much */
                s = start_fmt;
                u = 0;
                do {
                        if (print_type & (1 << u)) {
                                printf(s, pcounts[u]);
                                s = " %9"COUNT_FMT; /* Ok... restore the leading space. */
                        }
                        totals[u] += pcounts[u];
                } while (++u < 4);
                printf(fname_fmt, arg);
        }

        /* If more than one file was processed, we want the totals.  To save some
         * space, we set the pcounts ptr to the totals array.  This has the side
         * effect of trashing the totals array after outputting it, but that's
         * irrelavent since we no longer need it. */
        if (num_files > 1) {
                num_files = 0;                          /* Make sure we don't get here again. */
                arg = "total";
                pcounts = totals;
                --argv;
                goto OUTPUT;
        }

        fflush_stdout_and_exit(status);
}