Re: try command error codes, where documented?

Am 17.08.2024 um 09:09 schrieb et99:

On 8/16/2024 9:45 PM, greg wrote:

Am 16.08.24 um 20:28 schrieb et99:

Is there a good place to lookup the various error codes returned by tcl commands?
>
In the try command manual there's an example:
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try {
     set f [open /some/file/name w]
} trap {POSIX EISDIR} {} {
     puts "failed to open /some/file/name: it's a directory"
} trap {POSIX ENOENT} {} {
     puts "failed to open /some/file/name: it doesn't exist"
}
>
How did the writer of this example know about these two error cases since they are not documented in the manual under either try or open.
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Also, are POSIX error codes system independent?
>
>

>
Hello;
maybe this helps:
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https://www.tcl.tk/man/tcl8.6/TclCmd/tclvars.htm#M12
>
source code tcl 8.6
./tcl8.6.14/win/tclWinError.c
/.tcl8.6.14/generic/tclPosixStr.c
>
>
https://en.wikipedia.org/wiki/Errno.h

  Thanks for the links.
 I was afraid this was probably the only way to get the codes.
 I think this could make a useful TIP - to add an error section to all command man pages as is done in the linux man pages.
 If I were 30 years younger, with the inherent time and energy, I might have volunteered to do this, since it is obviously a tedious and perhaps thankless job.
 I guess I will just stick to using my if-catch-template and not try to differentiate the particular errors. Besides, only I ever use my programs anymore :)

Thank you for the words and the initiative.
Reality is worse. We are on 3 platforms.
So, we try to get the same error code on all of them.
Errors come often from system calls. On Posix systems, they are just put up to the script. On WIndows, Windows error codes are mapped to possix error codes, which works more or less...
Remark that error codes are also available by catch.
The advantage of try is that you have a cleanup case, which is always executed, even on error and on return.
so:
proc t {fn} {
try {
set f [open $fn]
set d [read $f]
return $d
} trap ...
} on ...
} finally {
     if {[info exists f]} {close $f}
}
}
Closes the file in any handling case. It is beautiful, that the finally happens after the return command and the return still works.
This is a constructed example. But it might be handy.
Take care,
Harald