[PATCH] BBB: sd_setup.sh: Change /bin/bash -> /bin/sh to solely adhere to POSIX shell constructs

Jarielle Catbagan jcatbagan93 at gmail.com
Sun Jul 12 01:48:28 UTC 2015


Interesting. On my machine /bin/sh is a symbolic link to /bin/bash.  I
went ahead and tried /bin/dash and the 'echo' command can interpret
backslash characters whereas echo on sh/bash, -e has to be specified
otherwise the characters are outputted as is.

I tried printf in bash/sh and dash, and the command seems to be more
compatible in both shells.  I think this would be the solution in that
all 'echo' commands are replaced with 'printf'.  What do you think?


On Sat, Jul 11, 2015 at 5:41 PM, Ed Sutter <edsutterjr at gmail.com> wrote:
> For my system, with bash the "echo -e" is fine, but with sh, it chokes...
>
> els:ps
>   PID TTY          TIME CMD
>  3938 pts/24   00:00:00 bash
>  3988 pts/24   00:00:00 ps
> els:echo "hello\n1\n2\n3\n"
> hello\n1\n2\n3\n
> els:echo -e "hello\n1\n2\n3\n"
> hello
> 1
> 2
> 3
>
> els:exec /bin/sh
> els:ps
>   PID TTY          TIME CMD
>  3938 pts/24   00:00:00 sh
>  3991 pts/24   00:00:00 ps
> els:echo "hello\n1\n2\n3\n"
> hello
> 1
> 2
> 3
>
> els:echo -e "hello\n1\n2\n3\n"
> -e hello
> 1
> 2
> 3
>
> els:
>
> Just noticed one other thing:
>
> els:ls -l /bin/sh
> lrwxrwxrwx 1 root root 4 Feb 19  2014 /bin/sh -> dash
> els:ls -l /bin/bash
> -rwxr-xr-x 1 root root 986672 Oct  7  2014 /bin/bash
>
>
> If you guys think my system is in a strange state; hence, I'm causing this
> confusion, I'll just commit it as is.
> Ed
>
> Hi Dr. Joel,
>
> On Sat, Jul 11, 2015 at 8:19 AM, Joel Sherrill
> <joel.sherrill at oarcorp.com> wrote:
>
> On July 11, 2015 10:06:09 AM CDT, Jarielle Catbagan <jcatbagan93 at gmail.com>
> wrote:
>
> Ed,
>
> Is there any indication as to why 'echo' is failing?  'echo' is not a
> built-in command for either shell interpreter as I was able to locate
> it as a separate program using both shells.  The -e option is to allow
> interpretation of backslash characters as I was using it for newlines
> and tabs.
>
> Do  sh -x and then try the command by hand at a prompt.
>
> Using sh -x, I issued
>
>         echo -e "test\t123"
>
> and it outputted
>
>         + echo -e 'test\t123'
>         test        123
>
> On Sat, Jul 11, 2015 at 7:51 AM, Jarielle Catbagan
> <jcatbagan93 at gmail.com> wrote:
>
> On Jul 11, 2015 7:17 AM, "Ed Sutter" <edsutterjr at gmail.com> wrote:
>
> Jarielle,
> Did you try running the script with that change?
> I applied the patch, then tried running it and it failed.
> Apparently 'echo' in sh is different than 'echo' in bash, at least
>
> it is
>
> for my system.
> Let me know.
> I had to remove the -e from the echo lines for it to work on my
> ubuntu14.04 system.
> You wanna test that and resubmit the patch or should I do it?
> Ed
>
> Hi Ed,
>
> After I changed it to 'sh' I was able to run it.  Ok, I'll look into
>
> it to
>
> see what the issue might be.
> _______________________________________________
>
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>
> --joel
>
>
>
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