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1 | .\" Copyright (c) 1990, 1991, 1993 | |
2 | .\" The Regents of the University of California. All rights reserved. | |
3 | .\" | |
4 | .\" Redistribution and use in source and binary forms, with or without | |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 4. Neither the name of the University nor the names of its contributors | |
13 | .\" may be used to endorse or promote products derived from this software | |
14 | .\" without specific prior written permission. | |
15 | .\" | |
16 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
17 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
18 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
19 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
20 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
21 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
22 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
23 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
24 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
25 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
26 | .\" SUCH DAMAGE. | |
27 | .\" | |
28 | .\" @(#)fgetln.3 8.3 (Berkeley) 4/19/94 | |
29 | .\" $FreeBSD: src/lib/libc/stdio/fgetln.3,v 1.10 2009/02/28 06:00:58 das Exp $ | |
30 | .\" | |
31 | .Dd April 19, 1994 | |
32 | .Dt FGETLN 3 | |
33 | .Os | |
34 | .Sh NAME | |
35 | .Nm fgetln | |
36 | .Nd get a line from a stream | |
37 | .Sh LIBRARY | |
38 | .Lb libc | |
39 | .Sh SYNOPSIS | |
40 | .In stdio.h | |
41 | .Ft char * | |
42 | .Fn fgetln "FILE *stream" "size_t *len" | |
43 | .Sh DESCRIPTION | |
44 | The | |
45 | .Fn fgetln | |
46 | function | |
47 | returns a pointer to the next line from the stream referenced by | |
48 | .Fa stream . | |
49 | This line is | |
50 | .Em not | |
51 | a C string as it does not end with a terminating | |
52 | .Dv NUL | |
53 | character. | |
54 | The length of the line, including the final newline, | |
55 | is stored in the memory location to which | |
56 | .Fa len | |
57 | points. | |
58 | (Note, however, that if the line is the last | |
59 | in a file that does not end in a newline, | |
60 | the returned text will not contain a newline.) | |
61 | .Sh RETURN VALUES | |
62 | Upon successful completion a pointer is returned; | |
63 | this pointer becomes invalid after the next | |
64 | .Tn I/O | |
65 | operation on | |
66 | .Fa stream | |
67 | (whether successful or not) | |
68 | or as soon as the stream is closed. | |
69 | Otherwise, | |
70 | .Dv NULL | |
71 | is returned. | |
72 | The | |
73 | .Fn fgetln | |
74 | function | |
75 | does not distinguish between end-of-file and error; the routines | |
76 | .Xr feof 3 | |
77 | and | |
78 | .Xr ferror 3 | |
79 | must be used | |
80 | to determine which occurred. | |
81 | If an error occurs, the global variable | |
82 | .Va errno | |
83 | is set to indicate the error. | |
84 | The end-of-file condition is remembered, even on a terminal, and all | |
85 | subsequent attempts to read will return | |
86 | .Dv NULL | |
87 | until the condition is | |
88 | cleared with | |
89 | .Xr clearerr 3 . | |
90 | .Pp | |
91 | The text to which the returned pointer points may be modified, | |
92 | provided that no changes are made beyond the returned size. | |
93 | These changes are lost as soon as the pointer becomes invalid. | |
94 | .Sh ERRORS | |
95 | .Bl -tag -width Er | |
96 | .It Bq Er EBADF | |
97 | The argument | |
98 | .Fa stream | |
99 | is not a stream open for reading. | |
100 | .It Bq Er ENOMEM | |
101 | The internal line buffer could not be expanded due to lack of available memory, | |
102 | or because it would need to expand beyond INT_MAX in size. | |
103 | .El | |
104 | .Pp | |
105 | The | |
106 | .Fn fgetln | |
107 | function | |
108 | may also fail and set | |
109 | .Va errno | |
110 | for any of the errors specified for the routines | |
111 | .Xr fflush 3 , | |
112 | .Xr malloc 3 , | |
113 | .Xr read 2 , | |
114 | .Xr stat 2 , | |
115 | or | |
116 | .Xr realloc 3 . | |
117 | .Sh SEE ALSO | |
118 | .Xr ferror 3 , | |
119 | .Xr fgets 3 , | |
120 | .Xr fgetwln 3 , | |
121 | .Xr fopen 3 , | |
122 | .Xr getline 3 , | |
123 | .Xr putc 3 | |
124 | .Sh HISTORY | |
125 | The | |
126 | .Fn fgetln | |
127 | function first appeared in | |
128 | .Bx 4.4 . |