summaryrefslogtreecommitdiffstats
path: root/lib/libc/stdio/getdelim.3
blob: 8ef2dca89d5c952f2213cf9f0038e71d3c726cfe (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
.\"	$OpenBSD: getdelim.3,v 1.5 2017/07/22 13:22:32 anton Exp $
.\"     $NetBSD: getdelim.3,v 1.9 2011/04/20 23:37:51 enami Exp $
.\"
.\" Copyright (c) 2009 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Roy Marples.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd $Mdocdate: July 22 2017 $
.Dt GETDELIM 3
.Os
.Sh NAME
.Nm getdelim ,
.Nm getline
.Nd read a delimited record from a stream
.\" .Sh LIBRARY
.\" .Lb libc
.Sh SYNOPSIS
.In stdio.h
.Ft ssize_t
.Fn getdelim "char ** restrict lineptr" "size_t * restrict n" "int delimiter" "FILE * restrict stream"
.Ft ssize_t
.Fn getline "char ** restrict lineptr" "size_t * restrict n" "FILE * restrict stream"
.Sh DESCRIPTION
The
.Fn getdelim
function reads from the
.Fa stream
until it encounters a character matching
.Fa delimiter ,
storing the input in
.Fa *lineptr .
The buffer is
.Dv NUL Ns No -terminated
and includes the delimiter.
The
.Fa delimiter
character must be representable as an unsigned char.
.Pp
If
.Fa *n
is non-zero, then
.Fa *lineptr
must be pre-allocated to at least
.Fa *n
bytes.
The buffer should be allocated dynamically;
it must be possible to
.Xr free 3
.Fa *lineptr .
.Fn getdelim
will
.Xr realloc 3
.Fa *lineptr
as necessary, updating
.Fa *n
to reflect the new size.
It is the responsibility of the caller to
.Xr free 3
.Fa *lineptr
when it is no longer needed.
Even when it fails,
.Fn getdelim
may update
.Fa *lineptr .
.Pp
The
.Fn getline
function is equivalent to
.Fn getdelim
with
.Fa delimiter
set to the newline character.
.Sh RETURN VALUES
The
.Fn getdelim
and
.Fn getline
functions return the number of characters read, including the delimiter.
If no characters were read and the stream is at end-of-file, the functions
return \-1.
If an error occurs, the functions return \-1 and the global variable
.Va errno
is set to indicate the error.
.Pp
The functions do not distinguish between end-of-file and error,
and callers must use
.Xr feof 3
and
.Xr ferror 3
to determine which occurred.
.Sh EXAMPLES
The following code fragment reads lines from a file and writes them to
standard output.
.Bd -literal -offset indent
char *line = NULL;
size_t linesize = 0;
ssize_t linelen;

while ((linelen = getline(\*[Am]line, \*[Am]linesize, fp)) != -1)
	fwrite(line, linelen, 1, stdout);

free(line);
if (ferror(fp))
	err(1, "getline");
.Ed
.Sh ERRORS
.Bl -tag -width [EOVERFLOW]
.It Bq Er EINVAL
.Fa lineptr
or
.Fa n
is a
.Dv NULL
pointer.
.It Bq Er EOVERFLOW
More than SSIZE_MAX characters were read without encountering the delimiter.
.El
.Pp
The
.Fn getdelim
and
.Fn getline
functions may also fail and set
.Va errno
for any of the errors specified in the routines
.Xr fflush 3 ,
.Xr malloc 3 ,
.Xr read 2 ,
.Xr stat 2 ,
or
.Xr realloc 3 .
.Sh SEE ALSO
.Xr ferror 3 ,
.Xr fgets 3 ,
.Xr fopen 3
.Sh STANDARDS
The
.Fn getdelim
and
.Fn getline
functions conform to
.St -p1003.1-2008 .