table of contents
FGETLN(3bsd) | 3bsd | FGETLN(3bsd) |
NAME¶
fgetln
—
get a line from a stream
LIBRARY¶
library “libbsd”SYNOPSIS¶
#include <stdio.h>
(See
libbsd(7) for include usage.)
char *
fgetln
(FILE
*stream, size_t
*len);
DESCRIPTION¶
Thefgetln
() function returns a pointer to the next line
from the stream referenced by stream. This line is
not a C string as it does not end with a terminating
NUL
character. The length of the line, including the
final newline, is stored in the memory location to which
len points and is guaranteed to be greater than 0 upon
successful completion. (Note, however, that if the line is the last in a file
that does not end in a newline, the returned text will not contain a newline.)
RETURN VALUES¶
Upon successful completion a pointer is returned; this pointer becomes invalid after the next I/O operation on stream (whether successful or not) or as soon as the stream is closed. Otherwise,NULL
is returned. The fgetln
()
function does not distinguish between end-of-file and error; the routines
feof(3) and ferror(3) must be used to
determine which occurred. If an error occurs, the global variable
errno is set to indicate the error. The end-of-file
condition is remembered, even on a terminal, and all subsequent attempts to
read will return NULL
until the condition is cleared
with clearerr(3).
The text to which the returned pointer points may be modified, provided that no changes are made beyond the returned size. These changes are lost as soon as the pointer becomes invalid.
ERRORS¶
- [
EBADF
] - The argument stream is not a stream open for reading.
The fgetln
() function may also fail and
set errno for any of the errors specified for the
routines fflush(3), malloc(3),
read(2), stat(2), or
realloc(3).
SEE ALSO¶
ferror(3), fgets(3), fgetwln(3bsd), fopen(3), putc(3)HISTORY¶
Thefgetln
() function first appeared in
4.4BSD.
April 19, 1994 | Linux 4.19.0-14-amd64 |