1.\" $NetBSD: fparseln.3,v 1.7 1999/07/02 15:49:12 simonb Exp $ 2.\" $FreeBSD: head/lib/libutil/fparseln.3 140081 2005-01-11 20:50:51Z ru $ 3.\" 4.\" Copyright (c) 1997 Christos Zoulas. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by Christos Zoulas. 17.\" 4. The name of the author may not be used to endorse or promote products 18.\" derived from this software without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30.\" 31.Dd May 24, 2020 32.Dt FPARSELN 3 33.Os 34.Sh NAME 35.Nm fparseln 36.Nd return the next logical line from a stream 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In sys/types.h 41.In stdio.h 42.Ft "char *" 43.Fo fparseln 44.Fa "FILE *stream" "size_t *len" "size_t *lineno" 45.Fa "const char delim[3]" "int flags" 46.Fc 47.Sh DESCRIPTION 48The 49.Fn fparseln 50function 51returns a pointer to the next logical line from the stream referenced by 52.Fa stream . 53This string is 54.Dv NUL 55terminated and it is dynamically allocated on each invocation. 56It is the 57responsibility of the caller to free the pointer. 58.Pp 59By default, if a character is escaped, both it and the preceding escape 60character will be present in the returned string. 61Various 62.Fa flags 63alter this behaviour. 64.Pp 65The meaning of the arguments is as follows: 66.Bl -tag -width "lineno" 67.It Fa stream 68The stream to read from. 69.It Fa len 70If not 71.Dv NULL , 72the length of the string is stored in the memory location to which it 73points. 74.It Fa lineno 75If not 76.Dv NULL , 77the value of the memory location to which is pointed to, is incremented 78by the number of lines actually read from the file. 79.It Fa delim 80Contains the escape, continuation, and comment characters. 81If a character is 82.Dv NUL 83then processing for that character is disabled. 84If 85.Dv NULL , 86all characters default to values specified below. 87The contents of 88.Fa delim 89is as follows: 90.Bl -tag -width "delim[0]" 91.It Fa delim[0] 92The escape character, which defaults to 93.Cm \e , 94is used to remove any special meaning from the next character. 95.It Fa delim[1] 96The continuation character, which defaults to 97.Cm \e , 98is used to indicate that the next line should be concatenated with the 99current one if this character is the last character on the current line 100and is not escaped. 101.It Fa delim[2] 102The comment character, which defaults to 103.Cm # , 104if not escaped indicates the beginning of a comment that extends until the 105end of the current line. 106.El 107.It Fa flags 108If non-zero, alter the operation of 109.Fn fparseln . 110The various flags, which may be 111.Em or Ns -ed 112together, are: 113.Bl -tag -width ".Dv FPARSELN_UNESCCOMM" 114.It Dv FPARSELN_UNESCCOMM 115Remove escape preceding an escaped comment. 116.It Dv FPARSELN_UNESCCONT 117Remove escape preceding an escaped continuation. 118.It Dv FPARSELN_UNESCESC 119Remove escape preceding an escaped escape. 120.It Dv FPARSELN_UNESCREST 121Remove escape preceding any other character. 122.It Dv FPARSELN_UNESCALL 123All of the above. 124.El 125.El 126.Sh RETURN VALUES 127Upon successful completion a pointer to the parsed line is returned; 128otherwise, 129.Dv NULL 130is returned. 131.Pp 132The 133.Fn fparseln 134function uses internally 135.Xr fgetln 3 , 136so all error conditions that apply to 137.Xr fgetln 3 , 138apply to 139.Fn fparseln . 140In addition 141.Fn fparseln 142may set 143.Va errno 144to 145.Er ENOMEM 146and return 147.Dv NULL 148if it runs out of memory. 149.Sh SEE ALSO 150.Xr fgetln 3 151.Sh HISTORY 152The 153.Fn fparseln 154function first appeared in 155.Nx 1.4 156and 157.Fx 4.0 . 158