Getline C Implementation

Linux implementation in the Toolchain, so here directly copy the implementation of Apple, so for memory allocation processing is clear.
/* getline.c--replacement for GNU C library function Getlinecopyright (c) 1993 free software Foundation, Inc.this progra M is free software;  You can redistribute it and/ormodify it under the terms of the GNU general public License aspublished by the free software Foundation; Either version 2 of Thelicense, or (at your option) any later version. Distributed in the hope that it'll be useful, butwithout any WARRANTY;  Without even the implied warranty ofmerchantability or FITNESS for A particular PURPOSE.  See the Gnugeneral public License for more details. *//* written by Jan Brittenson, [email protected] */#ifdef have_config_h#include <config.h> #endif # include & lt;sys/types.h> #include <stdio.h> #include <assert.h> #include <errno.h> #if stdc_headers# Include <stdlib.h> #elsechar *malloc (), *realloc (), #endif/* Always add @ least this many bytes when extending the  Buffer. */#define MIN_CHUNK 64/* Read up to (and including) a TerminatoR from STREAM to *lineptr + OFFSET (and null-terminate it).  *lineptr is a pointer returned from malloc (or NULL), pointing to *n characters of space.  It is realloc ' d as necessary.  Return the number of characters read (not including the null terminator), or-1 on Error or EOF.  On A-1 return, the caller should check feof (), if not then errno have been set to indicate the error.     */intgetstr (lineptr, N, Stream, terminator, offset) char **lineptr;     size_t *n;     FILE *stream;     char Terminator; int offset;  {int nchars_avail;/* allocated but unused chars in *lineptr. */char *read_pos;/* Where we ' re reading into *lineptr.  */INT ret;      if (!lineptr | |!n | |!stream) {errno = EINVAL;    return-1;  } if (!*lineptr) {*n = Min_chunk;      *lineptr = malloc (*n);  if (!*lineptr) {errno = Enomem;    return-1;} }  Nchars_avail = *n-offset;  Read_pos = *lineptr + offset;    for (;;)      {int Save_errno;      Register int c = GETC (stream);      Save_errno = errno; /* We always want at least one char left in the buffer, since we always (unless we get a error while reading the first CH  AR) nul-terminate the line buffer.      */Assert ((*lineptr + *n) = = (Read_pos + nchars_avail));  if (Nchars_avail < 2) {if (*n > Min_chunk) *n *= 2;  else *n + = Min_chunk;  Nchars_avail = *n + *lineptr-read_pos;  *lineptr = ReAlloc (*lineptr, *n);      if (!*lineptr) {errno = Enomem;    return-1;  } Read_pos = *n-nchars_avail + *lineptr;      ASSERT ((*lineptr + *n) = = (Read_pos + nchars_avail));}  if (Ferror (stream)) {/* might like to return partial line, but there are no place for us to store errno.  And we don ' t want to just lose errno.  */errno = Save_errno;      return-1;}  if (c = = EOF) {/* Return partial line, if any. */if (Read_pos = = *lineptr) return-1;      else break;}      *read_pos++ = C;      nchars_avail--;  if (c = = Terminator)/* Return the line.    */break;  }/* Done-nul terminate and return the number of chars read.  */*read_pos = ' + ';  ret = Read_pos-(*lineptr + offset); return ret;}     Intgetline (lineptr, N, Stream) char **lineptr;     size_t *n; FILE *stream; {return getstr (lineptr, N, stream, ' \ n ', 0);}

Getline C Implementation