The packaged script files use a mixture of #!/bin/sh and #!/bin/bash. Some of the bash files clearly contain bashisms, but some of them appear not to, and could get by with using #!/bin/sh. Specifically: sendsms, sms2unicode and unicode2sms.
Why do I care? I am using smstools3 on an embedded system using Busybox and bash is not installed. Yes, I can manually edit the scripts before installation, but it would be nice to not require that step. In addition, I am packaging smstools3 for OpenEmbedded and it would be nice to have those changes upstream, rather than carrying local patches. (FWIW, the only scripts actually included in the OE smstools3 package are the three I mentioned above. :-) So, it would be nice to have them changed.)
If someone knows of a reason bash is required, let me know and maybe I can rework the script(s) and submit patch to avoid need that bash feature.