Libc-1439.100.3.tar.gz

[apple/libc.git] / stdlib / FreeBSD / realpath.3

diff --git a/stdlib/FreeBSD/realpath.3 b/stdlib/FreeBSD/realpath.3
index dc6ba9abe92c5d9a6805c444521b6036bfe74832..07e9dcc95546bf3ba50674eeb3f7e554421f77af 100644 (file)
--- a/stdlib/FreeBSD/realpath.3
+++ b/stdlib/FreeBSD/realpath.3
@@ -31,88 +31,128 @@
 .\"     @(#)realpath.3 8.2 (Berkeley) 2/16/94
 .\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.14 2007/01/09 00:28:10 imp Exp $
 .\"
 .\"     @(#)realpath.3 8.2 (Berkeley) 2/16/94
 .\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.14 2007/01/09 00:28:10 imp Exp $
 .\"

-.Dd February 16, 1994
+.Dd April 5, 2008

 .Dt REALPATH 3
 .Os
 .Sh NAME
 .Nm realpath
 .Nd returns the canonicalized absolute pathname
 .Dt REALPATH 3
 .Os
 .Sh NAME
 .Nm realpath
 .Nd returns the canonicalized absolute pathname

-.Sh LIBRARY
-.Lb libc
+.\" .Sh LIBRARY
+.\" .Lb libc

 .Sh SYNOPSIS
 .Sh SYNOPSIS

-.In sys/param.h

 .In stdlib.h
 .Ft "char *"
 .In stdlib.h
 .Ft "char *"

-.Fn realpath "const char *pathname" "char resolved_path[PATH_MAX]"
+.Fo realpath
+.Fa "const char *restrict file_name"
+.Fa "char *restrict resolved_name"
+.Fc

 .Sh DESCRIPTION
 The
 .Fn realpath
 function resolves all symbolic links, extra
 .Dq /
 .Sh DESCRIPTION
 The
 .Fn realpath
 function resolves all symbolic links, extra
 .Dq /

-characters and references to
+characters, and references to

 .Pa /./
 and
 .Pa /../
 in
 .Pa /./
 and
 .Pa /../
 in

-.Fa pathname ,
-and copies the resulting absolute pathname into
-the memory referenced by
-.Fa resolved_path .
-The
-.Fa resolved_path
+.Fa file_name .
+If the
+.Fa resolved_name

 argument
 argument

+is non-NULL, the resulting absolute pathname is copied there (it

 .Em must
 refer to a buffer capable of storing at least
 .Dv PATH_MAX
 .Em must
 refer to a buffer capable of storing at least
 .Dv PATH_MAX

-characters.
+characters).
+.Pp
+As a permitted extension to the standard, if
+.Fa resolved_name
+is NULL, 
+memory is allocated for the resulting absolute pathname, and is returned by
+.Fn realpath .
+This memory should be freed by a call to
+.Xr free 3
+when no longer needed.

 .Pp
 The
 .Fn realpath
 function will resolve both absolute and relative paths
 and return the absolute pathname corresponding to
 .Pp
 The
 .Fn realpath
 function will resolve both absolute and relative paths
 and return the absolute pathname corresponding to

-.Fa pathname .
-All but the last component of
-.Fa pathname
+.Fa file_name .
+All components of
+.Fa file_name

 must exist when
 .Fn realpath
 is called.
 .Sh "RETURN VALUES"
 must exist when
 .Fn realpath
 is called.
 .Sh "RETURN VALUES"

-The
+On success, the

 .Fn realpath
 .Fn realpath

-function returns
-.Fa resolved_path
-on success.
+function returns the address of the resulting absolute pathname, which is
+.Fa resolved_name
+if it was non-NULL, or the address of newly allocated memory.

 If an error occurs,
 .Fn realpath
 returns
 If an error occurs,
 .Fn realpath
 returns

-.Dv NULL ,
-and
-.Fa resolved_path
-contains the pathname which caused the problem.
+.Dv NULL .
+If
+.Fa resolved_name
+was non-NULL, it will
+contain the pathname which caused the problem.
+.Sh VARIANTS
+Defining 
+.Dv _DARWIN_C_SOURCE
+or
+.Dv _DARWIN_BETTER_REALPATH
+before including stdlib.h will cause the provided implementation of
+.Fn realpath
+to use F_GETPATH from
+.Xr fcntl 2
+to discover the path.

 .Sh ERRORS
 The function
 .Fn realpath
 may fail and set the external variable
 .Va errno
 for any of the errors specified for the library functions
 .Sh ERRORS
 The function
 .Fn realpath
 may fail and set the external variable
 .Va errno
 for any of the errors specified for the library functions

+.Xr alloca 3 ,
+.Xr getattrlist 2 ,
+.Xr getcwd 3 ,

 .Xr lstat 2 ,
 .Xr lstat 2 ,

-.Xr readlink 2
+.Xr readlink 2 ,
+.Xr stat 2 ,

 and
 and

-.Xr getcwd 3 .
-.Sh CAVEATS
-This implementation of
+.Xr strdup 3 .
+.\" .Sh CAVEATS
+.\" This implementation of
+.\" .Fn realpath
+.\" differs slightly from the Solaris implementation.
+.\" The
+.\" .Bx 4.4
+.\" version always returns absolute pathnames,
+.\" whereas the Solaris implementation will,
+.\" under certain circumstances, return a relative
+.\" .Fa resolved_name
+.\" when given a relative
+.\" .Fa file_name .
+.Sh LEGACY SYNOPSIS
+.Fd #include <sys/param.h>
+.Fd #include <stdlib.h>
+.Pp
+The include file
+.In sys/param.h
+is necessary.
+.Sh LEGACY DESCRIPTION
+In legacy mode,
+the last component of
+.Fa file_name
+does not need to exist when

 .Fn realpath
 .Fn realpath

-differs slightly from the Solaris implementation.
-The
-.Bx 4.4
-version always returns absolute pathnames,
-whereas the Solaris implementation will,
-under certain circumstances, return a relative
-.Fa resolved_path
-when given a relative
-.Fa pathname .
+is called.

 .Sh "SEE ALSO"
 .Sh "SEE ALSO"

-.Xr getcwd 3
+.Xr free 3 ,
+.Xr getcwd 3 ,
+.Xr compat 5

 .Sh HISTORY
 The
 .Fn realpath
 .Sh HISTORY
 The
 .Fn realpath