| fgetln(3bsd) | 3bsd | fgetln(3bsd) |
fgetln — get a
line from a stream
library “libbsd”
#include <stdio.h>
(See libbsd(7) for include usage.)
char *
fgetln(FILE
*stream, size_t
*len);
The
fgetln()
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.)
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.
EBADF]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).
The fgetln() function first appeared in
4.4BSD.
| April 19, 1994 | Debian |