Subversion Repositories openrisc_2011-10-31

/* Copyright 2002, Red Hat Inc. - all rights reserved */

/*

FUNCTION

<<getdelim>>---read a line up to a specified line delimiter

INDEX

        getdelim

ANSI_SYNOPSIS

        #include <stdio.h>

        int getdelim(char **<[bufptr]>, size_t *<[n]>,

                     int <[delim]>, FILE *<[fp]>);

TRAD_SYNOPSIS

        #include <stdio.h>

        int getdelim(<[bufptr]>, <[n]>, <[delim]>, <[fp]>)

        char **<[bufptr]>;

        size_t *<[n]>;

        int <[delim]>;

        FILE *<[fp]>;

DESCRIPTION

<<getdelim>> reads a file <[fp]> up to and possibly including a specified

delimiter <[delim]>.  The line is read into a buffer pointed to

by <[bufptr]> and designated with size *<[n]>.  If the buffer is

not large enough, it will be dynamically grown by <<getdelim>>.

As the buffer is grown, the pointer to the size <[n]> will be

updated.

RETURNS

<<getdelim>> returns <<-1>> if no characters were successfully read;

otherwise, it returns the number of bytes successfully read.

At end of file, the result is nonzero.

PORTABILITY

<<getdelim>> is a glibc extension.

No supporting OS subroutines are directly required.

*/

#include <_ansi.h>

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include "local.h"

#define MIN_LINE_SIZE 4

#define DEFAULT_LINE_SIZE 128

ssize_t

_DEFUN(__getdelim, (bufptr, n, delim, fp),

       char **bufptr _AND

       size_t *n     _AND

       int delim     _AND

       FILE *fp)

{

  char *buf;

  char *ptr;

  size_t newsize, numbytes;

  int pos;

  int ch;

  int cont;

  if (fp == NULL || bufptr == NULL || n == NULL)

    {

      errno = EINVAL;

      return -1;

    }

  buf = *bufptr;

  if (buf == NULL || *n < MIN_LINE_SIZE)

    {

      buf = (char *)realloc (*bufptr, DEFAULT_LINE_SIZE);

      if (buf == NULL)

        {

          return -1;

        }

      *bufptr = buf;

      *n = DEFAULT_LINE_SIZE;

    }

  CHECK_INIT (_REENT, fp);

  _flockfile (fp);

  numbytes = *n;

  ptr = buf;

  cont = 1;

  while (cont)

    {

      /* fill buffer - leaving room for nul-terminator */

      while (--numbytes > 0)

        {

          if ((ch = getc_unlocked (fp)) == EOF)

            {

              cont = 0;

              break;

            }

          else

            {

              *ptr++ = ch;

              if (ch == delim)

                {

                  cont = 0;

                  break;

                }

            }

        }

      if (cont)

        {

          /* Buffer is too small so reallocate a larger buffer.  */

          pos = ptr - buf;

          newsize = (*n << 1);

          buf = realloc (buf, newsize);

          if (buf == NULL)

            {

              cont = 0;

              break;

            }

          /* After reallocating, continue in new buffer */

          *bufptr = buf;

          *n = newsize;

          ptr = buf + pos;

          numbytes = newsize - pos;

        }

    }

  _funlockfile (fp);

  /* if no input data, return failure */

  if (ptr == buf)

    return -1;

  /* otherwise, nul-terminate and return number of bytes read */

  *ptr = '\0';

  return (ssize_t)(ptr - buf);

}