xref: /freebsd/lib/libc/gen/confstr.3 (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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32.\"	@(#)confstr.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd June 4, 1993
36.Dt CONFSTR 3
37.Os BSD 4
38.Sh NAME
39.Nm confstr
40.Nd get string-valued configurable variables
41.Sh SYNOPSIS
42.Fd #include <unistd.h>
43.Ft size_t
44.Fn confstr "int name" "char *buf" "size_t len"
45.Sh DESCRIPTION
46.Bf -symbolic
47This interface is obsoleted by
48.Xr sysctl 3 .
49.Ef
50.Pp
51The
52.Fn confstr
53function provides a method for applications to get configuration
54defined string values.
55.Pp
56The
57.Fa name
58argument specifies the system variable to be queried.
59Symbolic constants for each name value are found in the include file
60.Li <unistd.h> .
61The
62.Fa len
63argument specifies the size of the buffer referenced by the
64argument
65.Fa buf .
66If
67.Fa len
68is non-zero,
69.Fa buf
70is a non-null pointer, and
71.Fa name
72has a value, up to
73.Fa len
74\- 1 bytes of the value are copied into the buffer
75.Fa buf .
76The copied value is always null terminated.
77.Pp
78The available values are as follows:
79.Pp
80.Bl -tag -width "123456"
81.Pp
82.It Li _CS_PATH
83Return a value for the
84.Ev PATH
85environment variable that finds all the standard utilities.
86.El
87.Sh RETURN VALUES
88If the call to
89.Fn confstr
90is not successful, \-1 is returned and
91.Va errno
92is set appropriately.
93Otherwise, if the variable does not have a configuration defined value,
940 is returned and
95.Va errno
96is not modified.
97Otherwise, the buffer size needed to hold the entire configuration-defined
98value is returned.
99If this size is greater than the argument
100.Fa len ,
101the string in
102.Fa buf
103was truncated.
104.Sh ERRORS
105The
106.Fn confstr
107function may fail and set
108.Va error
109for any of the errors specified for the library functions
110.Xr malloc 3
111and
112.Xr sysctl 3 .
113.Pp
114In addition, the following errors may be reported:
115.Bl -tag -width Er
116.It Bq Er EINVAL
117The value of the
118.Fa name
119argument is invalid.
120.Sh SEE ALSO
121.Xr sysctl 3
122.Sh HISTORY
123The
124.Fn confstr
125function first appeared in
126.Bx 4.4 .
127