Place the nul on the third line. For example: #!/bin/bash # # ^@ identify as a binary file ...
On Thu, Apr 6, 2023 at 4:03 AM Corinna Vinschen via Cygwin < cygwin@cygwin.com> wrote: > On Apr 6 04:43, Fergus Daly via Cygwin wrote: > > I have a "hash bang" bash shell script i.e. first line > > #! /bin/sh > > or equivalently > > #! /bin/bash > > For various reasons I want this file to be identified as binary so its > second line > > is the single character null \x00 showing up in some editors e.g. nano as > > ^@ > > This does not prevent the script from running to a successful conclusion. > > Or not until recently. Now the script fails with > > /home/user/bin/file.old.sh: cannot execute binary file > > Q1 - was bash recently updated? Would this explain the changed behaviour? > > bash was recently updated from 4.4.12 to 5.2.15. > > The behaviour is the same in bash on Linux. Take this file with > a \0 in line 2: > > $ cat -v x.sh > #! /bin/bash > ^@ > echo foo > $ bash --version | head -1 > GNU bash, version 5.2.15(1)-release (x86_64-redhat-linux-gnu) > $ ./x.sh > ./x.sh: ./x.sh: cannot execute binary file > > While dash on Linux runs the script: > > $ sed -i -e 's/bash/dash/' x.sh > $ ./x.sh > foo > > > Q2 - if so, is this newly introduced "glitch" known and presumably > > intended? Or an unintended consequence that will be retracted in a > > later update? > > Bash follows the POSIX standard: > > https://pubs.opengroup.org/onlinepubs/9699919799/utilities/sh.html#tag_20_117_07 > > https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_403 > > So I don't expect this will change any time soon. > > > Q3 - at 1/8 the size of bash and sh, I am not at all sure of the role > and reach of dash. > > Dash is a minimal shell with no bells and whistles. It loads ands runs > slightly faster than bash. If you only need bare minimum bourne shell > behaviour, it's a good choice for scripts. > > > Corinna > > -- > Problem reports: https://cygwin.com/problems.html > FAQ: https://cygwin.com/faq/ > Documentation: https://cygwin.com/docs.html > Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple > -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
