[SOLVED] loops in scripts

JM_T · 07-03-2012, 03:39 PM

I am trying to batch process some files. So far I have used only single files, using

for i in ax bx cx dx nx etc...
do
command1 (e.g. /../test$i)
command2 (e.g. /../test$i)
done

I have files that need to be "coupled".
e.g. ax with dx, bx with cx, nx with nnx, ....

all this is in a fairly random order and I have a table/matrix with the filenames coupled. They have to be processed together before going to the next one, and I can't figure out how to do it.
e.g. commands will look like
command1 ../../test/ax/dx
command2 ../../test/ax/dx

where the loop then should jump to
command1 ../../test/bx/cx
command2 ../../test/bx/cx

etc.

THANKS!!!!

montel · 07-03-2012, 04:55 PM

I don't fully understand what you are trying to do, some more explanation would be very helpful.

JM_T · 07-03-2012, 05:07 PM

Basically I need to use 2 linked variables in one command line, repeat a few commands with this set of variables. Then next 2 variables need to go through the same set of commands are unrelated to the first 2, etc.
With "for i in..." I have been able to do this type of a loop with a single variable, but combining multiple sets of 2 linked variables within one loop I have not been able to figure out.

Hope that clarifies it better, not sure how better to put it. Thanks

suicidaleggroll · 07-03-2012, 05:14 PM

Like this?

Code:

#!/bin/bash

arr1=("ax" "bx" "nx")
arr2=("dx" "cx" "nnx")

for ((i=0; i<${#arr1[@]}; i++)); do
   echo command1 ../../test/${arr1[$i]}/${arr2[$i]}
   echo command2 ../../test/${arr1[$i]}/${arr2[$i]}
done

Output is

Code:

command1 ../../test/ax/dx
command2 ../../test/ax/dx
command1 ../../test/bx/cx
command2 ../../test/bx/cx
command1 ../../test/nx/nnx
command2 ../../test/nx/nnx

Just remove the echo from the lines to actually run the commands, rather than just printing out what it would run.

grail · 07-03-2012, 08:57 PM

Another take would be to use your file with the pairings in it. Assuming this looks like:

Code:

$ cat pairing_file
ax dx
bx cx
nx nnx

We can then read this in with a while loop like so:

Code:

while read -r first second
do
    command1 "../../test/$first/$second"
    command2 "../../test/$first/$second"
done<pairing_file

JM_T · 07-04-2012, 11:55 AM

Thank you so much, that worked perfectly.

grail · 07-05-2012, 12:30 AM

Please remember to mark as SOLVED once you have a solution.

kgntech · 07-05-2012, 01:41 AM

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