osx man page for fgetln

FGETLN(3)						   BSD Library Functions Manual 						 FGETLN(3)

NAME
     fgetln -- get a line from a stream

LIBRARY
     Standard C Library (libc, -lc)

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 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.

     [ENOMEM]		The internal line buffer could not be expanded due to lack of available memory, or because it would need to expand beyond
			INT_MAX in size.

     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(3), fopen(3), getline(3), putc(3)

HISTORY
     The fgetln() function first appeared in 4.4BSD.

BSD
								  April 19, 1994							       BSD