I wrote a script to do backups on a ESXi it uses Busybox’s ASH, one thing I learned after spending hours debugging my scripts was that ASH does not support arrays so you have to do everything with temporary files.
There actually is an array in any POSIX shell. You get one array per file/function. It just feels bad to use it. You can abuse ‘set – 1 2 3 4’ to act as a proper array. You can then use ‘for’ without ‘in’ to iterate over it.
for i; do echo $i; done.
Use shift <number> to pop items off.
If I really have to use something more complex, I’ll reach for mkfifo instead so I can guarantee the data can only be consumed once without manipulating entries.
I wrote a script to do backups on a ESXi it uses Busybox’s ASH, one thing I learned after spending hours debugging my scripts was that ASH does not support arrays so you have to do everything with temporary files.
There actually is an array in any POSIX shell. You get one array per file/function. It just feels bad to use it. You can abuse ‘set – 1 2 3 4’ to act as a proper array. You can then use ‘for’ without ‘in’ to iterate over it.
for i; do echo $i; done.
Use shift <number> to pop items off.
If I really have to use something more complex, I’ll reach for mkfifo instead so I can guarantee the data can only be consumed once without manipulating entries.
Cool, good to know.