Страницы справочника OS X

Эта страница руководства является частью версии 5.0 Инструментов XCode

Читать страницы руководства

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 con-tain contain
     tain a newline.)

RETURN VALUES
     Upon successful completion a pointer is returned; this pointer becomes invalid after the next I/O oper-ation operation
     ation 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 vari-able variable
     able 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