xref: /freebsd/lib/libutil/fparseln.3 (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1.\"	$NetBSD: fparseln.3,v 1.7 1999/07/02 15:49:12 simonb Exp $
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3.\" Copyright (c) 1997 Christos Zoulas.  All rights reserved.
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30.Dd December 1, 1997
31.Dt FPARSELN 3
32.Os
33.Sh NAME
34.Nm fparseln
35.Nd return the next logical line from a stream
36.Sh LIBRARY
37.Lb libutil
38.Sh SYNOPSIS
39.In stdio.h
40.In libutil.h
41.Ft "char *"
42.Fo fparseln
43.Fa "FILE *stream" "size_t *len" "size_t *lineno"
44.Fa "const char delim[3]" "int flags"
45.Fc
46.Sh DESCRIPTION
47The
48.Fn fparseln
49function
50returns a pointer to the next logical line from the stream referenced by
51.Fa stream .
52This string is
53.Dv NUL
54terminated and it is dynamically allocated on each invocation.
55It is the
56responsibility of the caller to free the pointer.
57.Pp
58By default, if a character is escaped, both it and the preceding escape
59character will be present in the returned string.
60Various
61.Fa flags
62alter this behaviour.
63.Pp
64The meaning of the arguments is as follows:
65.Bl -tag -width "lineno"
66.It Fa stream
67The stream to read from.
68.It Fa len
69If not
70.Dv NULL ,
71the length of the string is stored in the memory location to which it
72points.
73.It Fa lineno
74If not
75.Dv NULL ,
76the value of the memory location to which is pointed to, is incremented
77by the number of lines actually read from the file.
78.It Fa delim
79Contains the escape, continuation, and comment characters.
80If a character is
81.Dv NUL
82then processing for that character is disabled.
83If
84.Dv NULL ,
85all characters default to values specified below.
86The contents of
87.Fa delim
88is as follows:
89.Bl -tag -width "delim[0]"
90.It Fa delim[0]
91The escape character, which defaults to
92.Cm \e ,
93is used to remove any special meaning from the next character.
94.It Fa delim[1]
95The continuation character, which defaults to
96.Cm \e ,
97is used to indicate that the next line should be concatenated with the
98current one if this character is the last character on the current line
99and is not escaped.
100.It Fa delim[2]
101The comment character, which defaults to
102.Cm # ,
103if not escaped indicates the beginning of a comment that extends until the
104end of the current line.
105.El
106.It Fa flags
107If non-zero, alter the operation of
108.Fn fparseln .
109The various flags, which may be
110.Em or Ns -ed
111together, are:
112.Bl -tag -width "FPARSELN_UNESCCOMM"
113.It Dv FPARSELN_UNESCCOMM
114Remove escape preceding an escaped comment.
115.It Dv FPARSELN_UNESCCONT
116Remove escape preceding an escaped continuation.
117.It Dv FPARSELN_UNESCESC
118Remove escape preceding an escaped escape.
119.It Dv FPARSELN_UNESCREST
120Remove escape preceding any other character.
121.It Dv FPARSELN_UNESCALL
122All of the above.
123.El
124.El
125.Sh RETURN VALUES
126Upon successful completion a pointer to the parsed line is returned;
127otherwise,
128.Dv NULL
129is returned.
130.Pp
131The
132.Fn fparseln
133function uses internally
134.Xr fgetln 3 ,
135so all error conditions that apply to
136.Xr fgetln 3 ,
137apply to
138.Fn fparseln .
139In addition
140.Fn fparseln
141may set
142.Va errno
143to
144.Er ENOMEM
145and return
146.Dv NULL
147if it runs out of memory.
148.Sh SEE ALSO
149.Xr fgetln 3
150.Sh HISTORY
151The
152.Fn fparseln
153function first appeared in
154.Nx 1.4
155and
156.Fx 4.0 .
157