GETDELIM(3) BSD Library Functions Manual GETDELIM(3)NAME
getdelim, getline — read a delimited record from a stream
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h>
ssize_t
getdelim(char ** restrict lineptr, size_t * restrict n, int delimiter,
FILE * restrict stream);
ssize_t
getline(char ** restrict lineptr, size_t * restrict n,
FILE * restrict stream);
DESCRIPTION
The getdelim() function reads from the stream until it encounters a char‐
acter matching delimiter, storing the input in *lineptr. The buffer is
NUL-terminated and includes the delimiter. The delimiter character must
be representable as an unsigned char.
If *n is non-zero, then *lineptr must be pre-allocated to at least *n
bytes. The buffer should be allocated dynamically; it must be possible
to free(3) *lineptr. getdelim() ensures that *lineptr is large enough to
hold the input, updating *n to reflect the new size.
The getline() function is equivalent to getdelim() with delimiter set to
the newline character.
RETURN VALUES
The getdelim() and getline() functions return the number of characters
read, including the delimiter. If no characters were read and the stream
is at end-of-file, the functions return -1. If an error occurs, the
functions return -1 and the global variable errno is set to indicate the
error.
The functions do not distinguish between end-of-file and error, and call‐
ers must use feof(3) and ferror(3) to determine which occurred.
EXAMPLES
The following code fragment reads lines from a file and writes them to
standard output.
char *line = NULL;
size_t linesize = 0;
ssize_t linelen;
while ((linelen = getline(&line, &linesize, fp)) != -1)
fwrite(line, linelen, 1, stdout);
if (ferror(fp))
perror("getline");
ERRORS
[EINVAL] lineptr or n is a NULL pointer.
[EOVERFLOW] More than SSIZE_MAX characters were read without encounter‐
ing the delimiter.
The getdelim() and getline() functions may also fail and set errno for
any of the errors specified in the routines fflush(3), malloc(3),
read(2), stat(2), or realloc(3).
SEE ALSOferror(3), fgets(3), fopen(3)STANDARDS
The getdelim() and getline() functions conform to IEEE Std 1003.1-2008
(“POSIX.1”).
BSD June 30, 2010 BSD
