.\" $OpenBSD: getdelim.3,v 1.7 2022/12/20 17:59:29 schwarze Exp $ .\" $NetBSD: getdelim.3,v 1.9 2011/04/20 23:37:51 enami Exp $ .\" .\" Copyright (c) 2009 The NetBSD Foundation, Inc. .\" All rights reserved. .\" .\" This code is derived from software contributed to The NetBSD Foundation .\" by Roy Marples. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: December 20 2022 $ .Dt GETDELIM 3 .Os .Sh NAME .Nm getdelim , .Nm getline .Nd read a delimited record from a stream .\" .Sh LIBRARY .\" .Lb libc .Sh SYNOPSIS .In stdio.h .Ft ssize_t .Fn getdelim "char ** restrict lineptr" "size_t * restrict n" "int delimiter" "FILE * restrict stream" .Ft ssize_t .Fn getline "char ** restrict lineptr" "size_t * restrict n" "FILE * restrict stream" .Sh DESCRIPTION The .Fn getdelim function reads from the .Fa stream until it encounters a character matching .Fa delimiter , storing the input in .Fa *lineptr . The buffer is .Dv NUL Ns No -terminated and includes the delimiter. The .Fa delimiter character must be representable as an .Vt unsigned char . .Pp If .Fa *n is non-zero, then .Fa *lineptr must be pre-allocated to at least .Fa *n bytes. The buffer should be allocated dynamically; it must be possible to .Xr free 3 .Fa *lineptr . .Fn getdelim will .Xr realloc 3 .Fa *lineptr as necessary, updating .Fa *n to reflect the new size. It is the responsibility of the caller to .Xr free 3 .Fa *lineptr when it is no longer needed. Even when it fails, .Fn getdelim may update .Fa *lineptr . .Pp The .Fn getline function is equivalent to .Fn getdelim with .Fa delimiter set to the newline character. .Sh RETURN VALUES The .Fn getdelim and .Fn getline functions return the number of characters read, including the delimiter. If no characters were read and the stream is at end-of-file, the functions return \-1. If an error occurs, the functions return \-1 and the global variable .Va errno is set to indicate the error. .Pp The functions do not distinguish between end-of-file and error, and callers must use .Xr feof 3 and .Xr ferror 3 to determine which occurred. .Sh EXAMPLES The following code fragment reads lines from a file and writes them to standard output. .Bd -literal -offset indent char *line = NULL; size_t linesize = 0; ssize_t linelen; while ((linelen = getline(\*[Am]line, \*[Am]linesize, fp)) != -1) fwrite(line, linelen, 1, stdout); free(line); if (ferror(fp)) err(1, "getline"); .Ed .Sh ERRORS .Bl -tag -width [EOVERFLOW] .It Bq Er EINVAL .Fa lineptr or .Fa n is a .Dv NULL pointer. .It Bq Er EOVERFLOW More than SSIZE_MAX characters were read without encountering the delimiter. .El .Pp The .Fn getdelim and .Fn getline functions may also fail and set .Va errno for any of the errors specified in the routines .Xr fflush 3 , .Xr malloc 3 , .Xr read 2 , .Xr stat 2 , or .Xr realloc 3 . .Sh SEE ALSO .Xr ferror 3 , .Xr fgets 3 , .Xr fopen 3 .Sh STANDARDS The .Fn getdelim and .Fn getline functions conform to .St -p1003.1-2008 . .Sh HISTORY These functions were ported from .Nx to .Ox 5.2 .