FGETLN(3) Library Routines FGETLN(3)
NAME
fgetln - get a line from a stream
SYNOPSIS
#include <stdio.h>
char *fgetln (FILE *stream, size_t *len);
DESCRIPTION
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. (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 new‐
line.)
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 oc‐
curred. If an error occurs, the global variable errno is set to indi‐
cate 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), fopen(3), putc(3)
HISTORY
The fgetln function first appeared in 4.4BSD.
GNO 19 April 1997 FGETLN(3)
Man(1) output converted with
man2html