FGETLN(3) BSD Programmer's Manual FGETLN(3)
fgetln - get a line from a stream
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. (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 oc-
curred. 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 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
ferror(3), fgets(3), fopen(3), putc(3)
The fgetln() function first appeared in 4.4BSD.
4.4BSD April 19, 1994 1