Purpose: Show how to create a temp file.
DL
Tcl doesn't have a built-in command to create a temporary file and there are no built-in variables for temp directories, so you have to do a little work.
Best is to figure out the temp directory separately. Then you can create multiple files in it.
switch $tcl_platform(platform) {
unix {
set tmpdir /tmp
} macintosh {
set tmpdir $env(TRASH_FOLDER) ;# a better place?
} default {
set tmpdir [pwd]
catch {set tmpdir $env(TMP)}
catch {set tmpdir $env(TEMP)}
}
}If you just want one temp file:
set filename [file join $tmpdir [pid]]
If you want multiple tmpfiles, consider appending things like the application name, counter, time stamp, etc. For example:
set file [file join $tmpdir $appname.[pid].[incr ::globalCounter]]
DKF - Or create in a subdirectory/subfolder
if {![file exists [file join $tmpdir [pid]]]} {
file mkdir [file join $tmpdir [pid]]
}
set file [file join $tmpdir [pid] [incr ::globalCounter]]Michael Schlenker - Be aware of potential race conditions while opening temp files. The linux secure programming howto has some nice examples for the linux platform: http://www.linuxdoc.org/HOWTO/Secure-Programs-HOWTO/avoid-race.html
To be sure to get a new tempfile (and not some evil symlink) try something like:
set access list RDWR CREAT EXCL TRUNC set perm 0600 if {catch {open $file $access $perm} fid} {