xref: /freebsd/lib/libutil/fparseln.3 (revision 2e22df0b1169383e119e1128a21966dee040214a)
1.\"	$NetBSD: fparseln.3,v 1.7 1999/07/02 15:49:12 simonb Exp $
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4.\" Copyright (c) 1997 Christos Zoulas.  All rights reserved.
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31.Dd December 1, 1997
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 libutil
39.Sh SYNOPSIS
40.Fd #include <stdio.h>
41.Fd #include <libutil.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 dynamicaly allocated on each invocation. It is the
56responsibility of the caller to free the pointer.
57.Pp
58By default, if a character is escaped, both it and the preceeding 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 preceeding an escaped comment.
115.It Dv FPARSELN_UNESCCONT
116Remove escape preceeding an escaped continuation.
117.It Dv FPARSELN_UNESCESC
118Remove escape preceeding an escaped escape.
119.It Dv FPARSELN_UNESCREST
120Remove escape preceeding any other character.
121.It Dv FPARSELN_UNESCALL
122All of the above.
123.El
124.Pp
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.Bq 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 .
156