[U-Boot-Users] Hush 'elif' operation?

Greetings
I'm trying to get as close to a switch statement in hush shell language as possible and thought that a set of if/then/elif/else would be tidier than nested if/then/else. It doesn't work how I expected however. The example below illustrates the problem - I was expecting execution after a true test (in the first 'if' in this case) to continue after the 'fi' but instead it ploughs through all the other executable (echo) statements having skipped the elif statements. It does correctly skip the else clause however :-))
Could someone assist in the navigation of this module to point out where would be a good place to start (i.e. some basic principles and assumptions of how the parser works).
[apologies for the word wrapping]
=>if iml; then echo "one"; elif iml; then echo "two"; elif iml; then echo "three"; else echo "four"; fi Image at 40340000: Image Name: Linux-2.4.22-20040129-12:57 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 630253 Bytes = 615.5 kB Load Address: 00000000 Entry Point: 00000000
one two three =>
Many thanks

Dear Robin,
in message 40197548.6060001@tait.co.nz you wrote:
I'm trying to get as close to a switch statement in hush shell language as possible and thought that a set of if/then/elif/else would be tidier than nested if/then/else. It doesn't work how I expected however. The example below illustrates the problem - I was expecting execution after a true test (in the first 'if' in this case) to continue after the 'fi' but instead it ploughs through all the other executable (echo) statements having skipped the elif statements. It does correctly skip the else clause however :-))
I confirm that this is a bug of HUSH.
The same problem is present in the HUSH shell of the most recent version of BusyBox, too (v1.00-pre7).
Could someone assist in the navigation of this module to point out where would be a good place to start (i.e. some basic principles and assumptions of how the parser works).
Well, please feel free to dig into the innards of HUSH (using the BusyBox implementation is probably much easier to debug).
We will look into this, too - as time permits.
Best regards,
Wolfgang Denk

Dear Robin,
in message 40197548.6060001@tait.co.nz you wrote:
I'm trying to get as close to a switch statement in hush shell language as possible and thought that a set of if/then/elif/else would be tidier than nested if/then/else. It doesn't work how I expected however. The
...
=>if iml; then echo "one"; elif iml; then echo "two"; elif iml; then echo "three"; else echo "four"; fi Image at 40340000: Image Name: Linux-2.4.22-20040129-12:57 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 630253 Bytes = 615.5 kB Load Address: 00000000 Entry Point: 00000000
one two three =>
I just checked in a patch that fixes this problem. Sorry this took so long.
Best regards,
Wolfgang Denk
participants (2)
-
Robin Gilks
-
Wolfgang Denk