xref: /freebsd/lib/libcompat/4.3/re_comp.3 (revision 23f282aa31e9b6fceacd449020e936e98d6f2298)
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32.\"     @(#)re_comp.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd June 4, 1993
36.Dt RE_COMP 3
37.Os
38.Sh NAME
39.Nm re_comp ,
40.Nm re_exec
41.Nd regular expression handler
42.Sh SYNOPSIS
43.Fd #include <unistd.h>
44.Ft char *
45.Fn re_comp "const char *s"
46.Ft int
47.Fn re_exec "const char *s"
48.Sh DESCRIPTION
49This interface is made obsolete by
50.Xr regex 3 .
51It is available from the compatibility library, libcompat.
52.Pp
53The
54.Fn re_comp
55function
56compiles a string into an internal form suitable for pattern matching.
57The
58.Fn re_exec
59function
60checks the argument string against the last string passed to
61.Fn re_comp .
62.Pp
63The
64.Fn re_comp
65function
66returns 0 if the string
67.Fa s
68was compiled successfully; otherwise a string containing an
69error message is returned.
70If
71.Fn re_comp
72is passed 0 or a null string, it returns without changing the currently
73compiled regular expression.
74.Pp
75The
76.Fn re_exec
77function
78returns 1 if the string
79.Fa s
80matches the last compiled regular expression, 0 if the string
81.Fa s
82failed to match the last compiled regular expression, and \-1 if the compiled
83regular expression was invalid (indicating an internal error).
84.Pp
85The strings passed to both
86.Fn re_comp
87and
88.Fn re_exec
89may have trailing or embedded newline characters;
90they are terminated by
91.Dv NUL Ns s.
92The regular expressions recognized are described in the manual entry for
93.Xr ed 1 ,
94given the above difference.
95.Sh DIAGNOSTICS
96The
97.Fn re_exec
98function
99returns \-1 for an internal error.
100.Pp
101The
102.Fn re_comp
103function
104returns one of the following strings if an error occurs:
105.Bd -unfilled -offset indent
106No previous regular expression,
107Regular expression too long,
108unmatched \e(,
109missing ],
110too many \e(\e) pairs,
111unmatched \e).
112.Ed
113.Sh SEE ALSO
114.Xr ed 1 ,
115.Xr egrep 1 ,
116.Xr ex 1 ,
117.Xr fgrep 1 ,
118.Xr grep 1 ,
119.Xr regex 3
120.Sh HISTORY
121The
122.Fn re_comp
123and
124.Fn re_exec
125functions appeared in
126.Bx 4.0 .
127