xref: /minix/lib/libc/stdio/fparseln.3 (revision 0a6a1f1d)
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25.Dd November 30, 2002
26.Dt FPARSELN 3
27.Os
28.Sh NAME
29.Nm fparseln
30.Nd return the next logical line from a stream
31.Sh LIBRARY
32.Lb libc
33.Sh SYNOPSIS
34.In stdio.h
35.Ft "char *"
36.Fo "fparseln"
37.Fa "FILE *stream" "size_t *len" "size_t *lineno"
38.Fa "const char delim[3]" "int flags"
39.Fc
40.Sh DESCRIPTION
41The
42.Fn fparseln
43function
44returns a pointer to the next logical line from the stream referenced by
45.Fa stream .
46This string is
47.Dv NUL
48terminated and it is dynamically allocated on each invocation.
49It is the responsibility of the caller to free the pointer.
50.Pp
51By default, if a character is escaped, both it and the preceding escape
52character will be present in the returned string.
53Various
54.Fa flags
55alter this behaviour.
56.Pp
57The meaning of the arguments is as follows:
58.Bl -tag -width "lineno"
59.It Fa stream
60The stream to read from.
61.It Fa len
62If not
63.Dv NULL ,
64the length of the string is stored in the memory location to which it
65points.
66.It Fa lineno
67If not
68.Dv NULL ,
69the value of the memory location to which is pointed to, is incremented
70by the number of lines actually read from the file.
71.It Fa delim
72Contains the escape, continuation, and comment characters.
73If a character is
74.Dv NUL
75then processing for that character is disabled.
76If
77.Dv NULL ,
78all characters default to values specified below.
79The contents of
80.Fa delim
81is as follows:
82.Bl -tag -width "delim[0]"
83.It Fa delim[0]
84The escape character, which defaults to
85.Cm \e ,
86is used to remove any special meaning from the next character.
87.It Fa delim[1]
88The continuation character, which defaults to
89.Cm \e ,
90is used to indicate that the next line should be concatenated with the
91current one if this character is the last character on the current line
92and is not escaped.
93.It Fa delim[2]
94The comment character, which defaults to
95.Cm # ,
96if not escaped indicates the beginning of a comment that extends until the
97end of the current line.
98.El
99.It Fa flags
100If non-zero, alter the operation of
101.Fn fparseln .
102The various flags, which may be
103.Em or Ns -ed
104together, are:
105.Bl -tag -width "FPARSELN_UNESCCOMM"
106.It Dv FPARSELN_UNESCCOMM
107Remove escape preceding an escaped comment.
108.It Dv FPARSELN_UNESCCONT
109Remove escape preceding an escaped continuation.
110.It Dv FPARSELN_UNESCESC
111Remove escape preceding an escaped escape.
112.It Dv FPARSELN_UNESCREST
113Remove escape preceding any other character.
114.It Dv FPARSELN_UNESCALL
115All of the above.
116.El
117.El
118.Sh RETURN VALUES
119Upon successful completion a pointer to the parsed line is returned;
120otherwise,
121.Dv NULL
122is returned.
123.Pp
124The
125.Fn fparseln
126function uses internally
127.Xr fgetln 3 ,
128so all error conditions that apply to
129.Xr fgetln 3 ,
130apply to
131.Fn fparseln .
132In addition
133.Fn fparseln
134may set
135.Va errno
136to
137.Bq Er ENOMEM
138and return
139.Dv NULL
140if it runs out of memory.
141.Sh SEE ALSO
142.Xr fgetln 3
143.Sh HISTORY
144The
145.Fn fparseln
146function first appeared in
147.Nx 1.4 .
148