xref: /freebsd/lib/libc/gen/confstr.3 (revision 58f0484fa251c266ede97b591b499fe3dd4f578e)
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32.\"	@(#)confstr.3	8.1 (Berkeley) 6/4/93
33.\"
34.Dd June 4, 1993
35.Dt CONFSTR 3
36.Os BSD 4
37.Sh NAME
38.Nm confstr
39.Nd get string-valued configurable variables
40.Sh SYNOPSIS
41.Fd #include <unistd.h>
42.Ft size_t
43.Fn confstr "int name" "char *buf" "size_t len"
44.Sh DESCRIPTION
45.Bf -symbolic
46This interface is obsoleted by sysctl(3).
47.Ef
48.Pp
49The
50.Fn confstr
51function provides a method for applications to get configuration
52defined string values.
53.Pp
54The
55.Fa name
56argument specifies the system variable to be queried.
57Symbolic constants for each name value are found in the include file
58.Li <unistd.h> .
59The
60.Fa len
61argument specifies the size of the buffer referenced by the
62argument
63.Fa buf .
64If
65.Fa len
66is non-zero,
67.Fa buf
68is a non-null pointer, and
69.Fa name
70has a value, up to
71.Fa len
72\- 1 bytes of the value are copied into the buffer
73.Fa buf .
74The copied value is always null terminated.
75.Pp
76The available values are as follows:
77.Pp
78.Bl -tag -width "123456"
79.Pp
80.It Li _CS_PATH
81Return a value for the
82.Ev PATH
83environment variable that finds all the standard utilities.
84.El
85.Sh RETURN VALUES
86If the call to
87.Nm confstr
88is not successful, \-1 is returned and
89.Va errno
90is set appropriately.
91Otherwise, if the variable does not have a configuration defined value,
920 is returned and
93.Va errno
94is not modified.
95Otherwise, the buffer size needed to hold the entire configuration-defined
96value is returned.
97If this size is greater than the argument
98.Fa len ,
99the string in
100.Fa buf
101was truncated.
102.Sh ERRORS
103The
104.Nm confstr
105function may fail and set
106.Va error
107for any of the errors specified for the library functions
108.Xr malloc 3
109and
110.Xr sysctl 3 .
111.Pp
112In addition, the following errors may be reported:
113.Bl -tag -width Er
114.It Bq Er EINVAL
115The value of the
116.Fa name
117argument is invalid.
118.Sh SEE ALSO
119.Xr sysctl 3
120.Sh HISTORY
121The
122.Nm confstr
123function first appeared in 4.4BSD.
124