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#ifndef GETLINE_H
#define GETLINE_H
#include <stdio.h>
#define restrict __restrict
typedef long long ssize_t;
ssize_t getline(char **restrict lineptr, size_t *restrict n, FILE *restrict stream);
ssize_t getdelim(char **restrict lineptr, size_t *restrict n, int delim, FILE *restrict stream);
/*
~$ export MANWIDTH=80
~$ man getline | col -b
GETLINE(3) Linux Programmer's Manual GETLINE(3)
NAME
getline, getdelim - delimited string input
SYNOPSIS
#include <stdio.h>
ssize_t getline(char **lineptr, size_t *n, FILE *stream);
ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getline(), getdelim():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE
DESCRIPTION
getline() reads an entire line from stream, storing the address of the
buffer containing the text into *lineptr. The buffer is null-termi-
nated and includes the newline character, if one was found.
If *lineptr is set to NULL and *n is set 0 before the call, then get-
line() will allocate a buffer for storing the line. This buffer should
be freed by the user program even if getline() failed.
Alternatively, before calling getline(), *lineptr can contain a pointer
to a malloc(3)-allocated buffer *n bytes in size. If the buffer is not
large enough to hold the line, getline() resizes it with realloc(3),
updating *lineptr and *n as necessary.
In either case, on a successful call, *lineptr and *n will be updated
to reflect the buffer address and allocated size respectively.
getdelim() works like getline(), except that a line delimiter other
than newline can be specified as the delimiter argument. As with get-
line(), a delimiter character is not added if one was not present in
the input before end of file was reached.
RETURN VALUE
On success, getline() and getdelim() return the number of characters
read, including the delimiter character, but not including the termi-
nating null byte ('\0'). This value can be used to handle embedded
null bytes in the line read.
Both functions return -1 on failure to read a line (including end-of-
file condition). In the event of an error, errno is set to indicate
the cause.
ERRORS
EINVAL Bad arguments (n or lineptr is NULL, or stream is not valid).
ENOMEM Allocation or reallocation of the line buffer failed.
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(7).
+------------------------------------------------+
¦Interface ¦ Attribute ¦ Value ¦
+----------------------+---------------+---------¦
¦getline(), getdelim() ¦ Thread safety ¦ MT-Safe ¦
+------------------------------------------------+
CONFORMING TO
Both getline() and getdelim() were originally GNU extensions. They
were standardized in POSIX.1-2008.
EXAMPLE
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
int
main(int argc, char *argv[])
{
FILE *stream;
char *line = NULL;
size_t len = 0;
ssize_t nread;
if (argc != 2) {
fprintf(stderr, "Usage: %s <file>\n", argv[0]);
exit(EXIT_FAILURE);
}
stream = fopen(argv[1], "r");
if (stream == NULL) {
perror("fopen");
exit(EXIT_FAILURE);
}
while ((nread = getline(&line, &len, stream)) != -1) {
printf("Retrieved line of length %zu:\n", nread);
fwrite(line, nread, 1, stdout);
}
free(line);
fclose(stream);
exit(EXIT_SUCCESS);
}
SEE ALSO
read(2), fgets(3), fopen(3), fread(3), scanf(3)
COLOPHON
This page is part of release 5.05 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2019-03-06 GETLINE(3)
*/
#endif /* GETLINE_H */
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