source: MondoRescue/branches/3.0/mindi-busybox/libbb/fgets_str.c@ 2899

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) many different people.
 * If you wrote this, please acknowledge your work.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"

static char *xmalloc_fgets_internal(FILE *file, const char *terminating_string, int chop_off, size_t *maxsz_p)
{
    char *linebuf = NULL;
    const int term_length = strlen(terminating_string);
    int end_string_offset;
    int linebufsz = 0;
    int idx = 0;
    int ch;
    size_t maxsz = *maxsz_p;

    while (1) {
        ch = fgetc(file);
        if (ch == EOF) {
            if (idx == 0)
                return linebuf; /* NULL */
            break;
        }

        if (idx >= linebufsz) {
            linebufsz += 200;
            linebuf = xrealloc(linebuf, linebufsz);
            if (idx >= maxsz) {
                linebuf[idx] = ch;
                idx++;
                break;
            }
        }

        linebuf[idx] = ch;
        idx++;

        /* Check for terminating string */
        end_string_offset = idx - term_length;
        if (end_string_offset >= 0
         && memcmp(&linebuf[end_string_offset], terminating_string, term_length) == 0
        ) {
            if (chop_off)
                idx -= term_length;
            break;
        }
    }
    /* Grow/shrink *first*, then store NUL */
    linebuf = xrealloc(linebuf, idx + 1);
    linebuf[idx] = '\0';
    *maxsz_p = idx;
    return linebuf;
}

/* Read up to TERMINATING_STRING from FILE and return it,
 * including terminating string.
 * Non-terminated string can be returned if EOF is reached.
 * Return NULL if EOF is reached immediately.  */
char* FAST_FUNC xmalloc_fgets_str(FILE *file, const char *terminating_string)
{
    size_t maxsz = INT_MAX - 4095;
    return xmalloc_fgets_internal(file, terminating_string, 0, &maxsz);
}

char* FAST_FUNC xmalloc_fgets_str_len(FILE *file, const char *terminating_string, size_t *maxsz_p)
{
    size_t maxsz;

    if (!maxsz_p) {
        maxsz = INT_MAX - 4095;
        maxsz_p = &maxsz;
    }
    return xmalloc_fgets_internal(file, terminating_string, 0, maxsz_p);
}

char* FAST_FUNC xmalloc_fgetline_str(FILE *file, const char *terminating_string)
{
    size_t maxsz = INT_MAX - 4095;
    return xmalloc_fgets_internal(file, terminating_string, 1, &maxsz);
}