xref: /openbsd-src/lib/libc/string/strchr.3 (revision 0b7734b3d77bb9b21afec6f4621cae6c805dbd45)
1.\"	$OpenBSD: strchr.3,v 1.12 2015/11/24 09:14:35 daniel Exp $
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34.Dd $Mdocdate: November 24 2015 $
35.Dt STRCHR 3
36.Os
37.Sh NAME
38.Nm strchr ,
39.Nm index
40.Nd locate first occurrence of a character in a string
41.Sh SYNOPSIS
42.In string.h
43.Ft char *
44.Fn strchr "const char *s" "int c"
45.In strings.h
46.Ft char *
47.Fn index "const char *s" "int c"
48.Sh DESCRIPTION
49The
50.Fn strchr
51function locates the first occurrence of the character
52.Fa c
53in the string
54.Fa s .
55The terminating NUL character is considered part of the string.
56If
57.Fa c
58is
59.Ql \e0 ,
60.Fn strchr
61locates the terminating
62.Ql \e0 .
63.Pp
64The
65.Fn index
66function is an old synonym for
67.Fn strchr .
68.Sh RETURN VALUES
69The
70.Fn strchr
71function returns a pointer to the located character or
72.Dv NULL
73if the character does not appear in the string.
74.Sh EXAMPLES
75After the following call to
76.Fn strchr ,
77.Va p
78will point to the string
79.Qq oobar :
80.Bd -literal -offset indent
81char *p;
82char *s = "foobar";
83
84p = strchr(s, 'o');
85.Ed
86.Sh SEE ALSO
87.Xr memchr 3 ,
88.Xr strcspn 3 ,
89.Xr strpbrk 3 ,
90.Xr strrchr 3 ,
91.Xr strsep 3 ,
92.Xr strspn 3 ,
93.Xr strstr 3 ,
94.Xr strtok 3 ,
95.Xr wcschr 3
96.Sh STANDARDS
97The
98.Fn strchr
99function conforms to
100.St -ansiC .
101.Pp
102The
103.Fn index
104function is deprecated and shouldn't be used in new code.
105.Sh HISTORY
106The
107.Fn index
108function first appeared in
109.At v7 .
110The
111.Fn strchr
112function first appeared in
113.At III
114and was reimplemented for
115.Bx 4.3 Tahoe .
116