xref: /freebsd/lib/libc/gen/confstr.3 (revision e627b39baccd1ec9129690167cf5e6d860509655)
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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
47.Xr sysctl 3 .
48.Ef
49.Pp
50The
51.Fn confstr
52function provides a method for applications to get configuration
53defined string values.
54.Pp
55The
56.Fa name
57argument specifies the system variable to be queried.
58Symbolic constants for each name value are found in the include file
59.Li <unistd.h> .
60The
61.Fa len
62argument specifies the size of the buffer referenced by the
63argument
64.Fa buf .
65If
66.Fa len
67is non-zero,
68.Fa buf
69is a non-null pointer, and
70.Fa name
71has a value, up to
72.Fa len
73\- 1 bytes of the value are copied into the buffer
74.Fa buf .
75The copied value is always null terminated.
76.Pp
77The available values are as follows:
78.Pp
79.Bl -tag -width "123456"
80.Pp
81.It Li _CS_PATH
82Return a value for the
83.Ev PATH
84environment variable that finds all the standard utilities.
85.El
86.Sh RETURN VALUES
87If the call to
88.Fn confstr
89is not successful, \-1 is returned and
90.Va errno
91is set appropriately.
92Otherwise, if the variable does not have a configuration defined value,
930 is returned and
94.Va errno
95is not modified.
96Otherwise, the buffer size needed to hold the entire configuration-defined
97value is returned.
98If this size is greater than the argument
99.Fa len ,
100the string in
101.Fa buf
102was truncated.
103.Sh ERRORS
104The
105.Fn confstr
106function may fail and set
107.Va error
108for any of the errors specified for the library functions
109.Xr malloc 3
110and
111.Xr sysctl 3 .
112.Pp
113In addition, the following errors may be reported:
114.Bl -tag -width Er
115.It Bq Er EINVAL
116The value of the
117.Fa name
118argument is invalid.
119.Sh SEE ALSO
120.Xr sysctl 3
121.Sh HISTORY
122The
123.Fn confstr
124function first appeared in
125.Bx 4.4 .
126