xref: /freebsd/lib/libpathconv/rel2abs.3 (revision 3c5ba95ad12285ad37c182a4bfc1b240ec6d18a7)
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2.\" Copyright (c) 1997 Shigio Yamaguchi. All rights reserved.
3.\" Copyright (c) 1999 Tama Communications Corporation. All rights reserved.
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26.\" $FreeBSD$
27.\"
28.Dd Dec 3, 1997"
29.Dt REL2ABS 3
30.Os
31.Sh NAME
32.Nm rel2abs
33.Nd make an absolute path name from a relative path name
34.Sh SYNOPSIS
35.Ft "char *"
36.Fn rel2abs "const char *path" "const char *base" "char *result" "size_t size"
37.Sh DESCRIPTION
38The
39.Fn rel2abs
40function makes an absolute path name from a relative path name
41.Fa path
42based on a directory
43.Fa base
44and copies the resulting path name into the memory referenced by
45.Fa result .
46The
47.Fa result
48argument must refer to a buffer capable of storing at least
49.Fa size
50character
51
52The resulting path name may include symbolic links.
53.Fn abs2rel
54doesn't check whether or not any path exists.
55.Sh "RETURN VALUES"
56The
57.Fn rel2abs
58function returns absolute path name on success.
59If an error occurs, it returns
60.Dv NULL .
61.Sh ERRORS
62The
63.Fn rel2abs
64function may fail and set the external variable
65.Va errno
66to indicate the error.
67.Bl -tag -width Er
68.It Bq Er EINVAL
69The
70.Fa base
71directory isn't an absolute path name or the
72.Fa size
73argument is zero.
74.It Bq Er ERANGE
75The
76.Fa size
77argument is greater than zero but smaller than the length of the pathname plus 1
78.Sh EXAMPLE
79    char result[MAXPATHLEN];
80    char *path = rel2abs("../../src/sys", "/usr/local/lib", result, MAXPATHLEN);
81
82yields:
83
84    path == "/usr/src/sys"
85
86Similarly,
87
88    path1 = rel2abs("src/sys", "/usr", result, MAXPATHLEN);
89    path2 = rel2abs(".", "/usr/src/sys", result, MAXPATHLEN);
90
91yields:
92
93    path1 == "/usr/src/sys"
94    path2 == "/usr/src/sys"
95.Sh "SEE ALSO"
96.Xr abs2rel 3
97.Sh AUTHORS
98Shigio Yamaguchi (shigio@tamacom.com)
99