summaryrefslogtreecommitdiffstats
path: root/doc/file.n
diff options
context:
space:
mode:
authordkf <donal.k.fellows@manchester.ac.uk>2007-07-04 13:25:53 (GMT)
committerdkf <donal.k.fellows@manchester.ac.uk>2007-07-04 13:25:53 (GMT)
commit726415ce000fd8fd519c61d004b3fb673977ef50 (patch)
tree9bdb4e78ebe8fe9ed13ff9265ae7379467f14fd9 /doc/file.n
parentef369d0c5ca00cc8fad599ea3c4dfc7df33e442f (diff)
downloadtcl-726415ce000fd8fd519c61d004b3fb673977ef50.zip
tcl-726415ce000fd8fd519c61d004b3fb673977ef50.tar.gz
tcl-726415ce000fd8fd519c61d004b3fb673977ef50.tar.bz2
Minor formatting fixes and additional notes on portability of [file]
Diffstat (limited to 'doc/file.n')
-rw-r--r--doc/file.n10
1 files changed, 6 insertions, 4 deletions
diff --git a/doc/file.n b/doc/file.n
index d8e4938..28599bf 100644
--- a/doc/file.n
+++ b/doc/file.n
@@ -5,7 +5,7 @@
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
-'\" RCS: @(#) $Id: file.n,v 1.43 2007/04/05 14:08:40 dkf Exp $
+'\" RCS: @(#) $Id: file.n,v 1.44 2007/07/04 13:25:53 dkf Exp $
'\"
.so man.macros
.TH file n 8.3 Tcl "Tcl Built-In Commands"
@@ -427,8 +427,11 @@ Returns \fB1\fR if file \fIname\fR is writable by the current user,
.TP
\fBUnix\fR\0\0\0\0\0\0\0
.
-These commands always operate using the real user and group identifiers,
-not the effective ones.
+The subcommands that test whether a particular mode of access is permitted
+always operate using the real user and group identifiers, not the effective
+ones. As such, robust code should just \fBopen\fR a file for reading instead
+of testing to see whether it is readable with \fBfile readable\fR. This also
+avoids potential race conditions.
.SH EXAMPLES
This procedure shows how to search for C files in a given directory
that have a correspondingly-named object file in the current
@@ -470,6 +473,5 @@ if {![\fBfile isdirectory\fR [\fBfile dirname\fR $newName]]} {
.SH "SEE ALSO"
chan(n), close(n), eof(n), fblocked(n), filename(n), flush(n), gets(n),
open(n), seek(n), tell(n)
-
.SH KEYWORDS
attributes, copy files, delete files, directory, file, move files, name, rename files, stat