This page describes how to convert a string to or from the GSM 03.38 character set.
Requirements
The non-null 0 character "@"
In the GSM 03.38 character set, the character "@" is encoded as 0x00. encoding convertto interprets such characters as "not convertible" and uses the fallback character "?".
Example:
set gsmString [encoding convertto gsm0338 "[email protected]"] # will return me?domain.com instead of me\x00domain.com
Workarounds
# The string is split at each "@", and the pieces are converted
# separately.
proc toGsm {aString} {
set partsWithoutAt [split $aString "@"]
set convertedPartsWithoutAt {}
foreach part $partsWithoutAt {
lappend convertedPartsWithoutAt [encoding convertto gsm0338 $part]
}
return [join $convertedPartsWithoutAt "\x00"]
}An alternative workaround, which is shorter but relies on an implementation detail of encoding convertto:
proc toGsm {aString} {
return [encoding convertto gsm0338 [string map {@ \x00} $aString] ]
}Lars H, 4 July 2005: I wouldn't label that as an implementation detail of encoding convertto; aren't you simply using the fact that gsm0338 maps NUL to itself? The string map maps \x40 to \x00.
As for the encoding error, is this a shortcoming in the encoding mechanism (impossible to map non-NUL characters to NUL) or an error in the particular encoding definition file? I wouldn't be entirely surprised if other languages have trouble with NULs in strings, but Tcl handles it correctly AFAIK.
Category?