Tcl proc to verify Numeric value

Mike,

Have you looked at the string command?

I believe it has a sub function to check for digits (numerics).

There is also a ctype function but I believe string is the preferred function.

Greetings,

  You may wish to try a regexp command that returns either a 1 or 0 depending on the results of the pattern match.  I was playing around with a regexp for all numeric when this post hit my inbox – see results below.

Handles empty string as well.  Hope this helps.

Read: from beginning of string to end of string all digits one or more are present –  BobR

regexp -all {^[0-9]+$} $val

tcl>set val 1234567890

1234567890

tcl>regexp -all {^[0-9]+$} $val

1

tcl>set val abc123bbb

abc123bbb

tcl>regexp -all {^[0-9]+$} $val

0

tcl>set val “”

tcl>regexp -all {^[0-9]+$} $val

0

tcl>set val 123456789o   <– lower case letter oh

123456789o

tcl>regexp -all {^[0-9]+$} $val

0

tcl>set val 3

3

tcl>regexp -all {^[0-9]+$} $val

1

set out [lindex $xlateInVals 0]

set len [string length $out]

if [cequal $len “8”] {

set out “Y”

}

set xlateOutVals $out

We use ctype, also don’t forget to return xlateOutVals as a list.

set out [lindex $xlateInVals 0]

set len [string length $out]

if [cequal $len “8”] && [ctype digit $out] {

set out “Y”

}

set xlateOutVals

Stay away from the “c” commands provied by the extended Tcl library.  There are core commands that do the same thing which are much better

Take a look at the string is command    

           if {![string is digit $val]} {echo $val is not all digits or empty string}

Note the above is true if all digits or the empty string.  If you do not want it to be true for the empty string, use the -strict flag

           if {![string is digit -strict $val]} {echo $val is not all digits}

Charlie,

Thanks – I do not have my work laptop with me and I could not for the life of me remember the string subfunction for checking type.