xref: /freebsd/lib/libutil/fparseln.3 (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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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.In stdio.h
41.In 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 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 "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.Pp
126.El
127.Sh RETURN VALUES
128Upon successful completion a pointer to the parsed line is returned;
129otherwise,
130.Dv NULL
131is returned.
132.Pp
133The
134.Fn fparseln
135function uses internally
136.Xr fgetln 3 ,
137so all error conditions that apply to
138.Xr fgetln 3 ,
139apply to
140.Fn fparseln .
141In addition
142.Fn fparseln
143may set
144.Va errno
145to
146.Er ENOMEM
147and return
148.Dv NULL
149if it runs out of memory.
150.Sh SEE ALSO
151.Xr fgetln 3
152.Sh HISTORY
153The
154.Fn fparseln
155function first appeared in
156.Nx 1.4
157and
158.Fx 4.0 .
159