getline.c
2.75 KB
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/* GNU mailutils - a suite of utilities for electronic mail
Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Library Public License as published by
the Free Software Foundation; either version 2, 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 of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* First implementation by Alain Magloire */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
ssize_t
getline (char **lineptr, size_t *n, FILE *stream)
{
return getdelim (lineptr, n, '\n', stream);
}
#ifndef HAVE_GETDELIM
/* Default value for line length. */
static const int line_size = 128;
ssize_t
getdelim (char **lineptr, size_t *n, int delim, FILE *stream)
{
int indx = 0;
int c;
/* Sanity checks. */
if (lineptr == NULL || n == NULL || stream == NULL)
return -1;
/* Allocate the line the first time. */
if (*lineptr == NULL)
{
*lineptr = malloc (line_size);
if (*lineptr == NULL)
return -1;
*n = line_size;
}
while ((c = getc (stream)) != EOF)
{
/* Check if more memory is needed. */
if (indx >= *n)
{
*lineptr = realloc (*lineptr, *n + line_size);
if (*lineptr == NULL)
return -1;
*n += line_size;
}
/* Push the result in the line. */
(*lineptr)[indx++] = c;
/* Bail out. */
if (c == delim)
break;
}
/* Make room for the null character. */
if (indx >= *n)
{
*lineptr = realloc (*lineptr, *n + line_size);
if (*lineptr == NULL)
return -1;
*n += line_size;
}
/* Null terminate the buffer. */
(*lineptr)[indx++] = 0;
/* The last line may not have the delimiter, we have to
* return what we got and the error will be seen on the
* next iteration. */
return (c == EOF && (indx - 1) == 0) ? -1 : indx - 1;
}
#endif /* HAVE_GETDELIM */
#ifdef STANDALONE
int main(void)
{
FILE * fp;
char * line = NULL;
size_t len = 0;
ssize_t read;
fp = fopen("/etc/passwd", "r");
if (fp == NULL)
exit(EXIT_FAILURE);
while ((read = getline(&line, &len, fp)) != -1) {
printf("Retrieved line of length %zu :\n", read);
printf("%s", line);
}
if (line)
free(line);
return EXIT_SUCCESS;
}
#endif