What's the difference between !/bin/sh and !/bin/bash?

[NickBiker]

Hi!

Just wondered if anyone could help with this slightly odd problem!

In the Puppy console I can type:

Code: Select all

#alpha="abcdef"
#echo ${alpha/abc/xyz}
#xyzdef

Which is how it should be using the substition {a/b/n}

BUT if I do the same thing in a standard script I get an error:

Code: Select all

#!/bin/sh

alpha="abcdef"
echo ${alpha/abc/xyz}

I get: ...4: Syntax error: Bad Substitution

Am I going mad!

[MU]

#!/bin/bash
not
#!/bin/sh

Mark

[NickBiker]

#!/bin/bash
not
#!/bin/sh

Mark

Hi!

Oh! I thought /bin/sh would be a symbolic link to bash? What is it then?!

Thanks for help

[MU]

no, sh is a symbolic link to busybox.
Busybox has the more limited ash -shell, that is used in image.gz when Puppy boots.
ash has less possibilities than bash, but allows to keep image.gz small.

Mark

[NickBiker]

no, sh is a symbolic link to busybox.
Busybox has the more limited ash -shell, that is used in image.gz when Puppy boots.
ash has less possibilities than bash, but allows to keep image.gz small.

Mark

Hi Mark

Thanks for help! I was wondered if I was going mad a could not get for loops to work either! Still it is good practice to work out ways to do things using a limited command set!!