Execute command stored in variable

RomanW

I want to merge many log files (values??.tmp) to one file (values.log):

e.g. cat values1.tmp values2.tmp >> values.log

I made this:

Bash

#!/bin/bash
prefix="values"
suffix=".tmp"
cmd="cat"
for i in `seq 1 2`;
do
  name=$prefix$i$suffix
  cmd=$cmd" "$name
done    
cmd=$cmd" >> values.log"
echo $cmd

Alles anzeigen

How to execute $cmd at the prompt as typed?

Plantschkuh!

This should work:

Code

`$cmd`

(backquotes!) as should this:

Code

echo $cmd | xargs

RomanW

Ok, I tried this:

Bash

#!/bin/bash
clear
prefix="Comps"
suffix=".tmp"
cmd="cat"
for i in `seq 1 2`;
do
  file=$prefix$i$suffix
  cmd=$cmd" "$file
done    
cmd=$cmd" >> Comps_.log"
#echo $cmd | xargs
`$cmd`

Alles anzeigen

But I get this:

Code

cat: >>: No such file or directory
cat: Comps_.log: No such file or directory
test.sh: line 13: local: can only be used in a function

How handling the >> ?

Stefan Kögl

Zitat von RomanW

How handling the >> ?

You could try `$cmd >> somefile`

Kampi

Bash

#!/bin/bash
prefix="values"
suffix=".tmp"
cmd="cat"
merged="values.log"


rm -f $merged
for i in `seq 1 2`;
do
  name=$prefix$i$suffix
  $cmd $name >> $merged
done

Alles anzeigen

[edit]
or at the command prompt:

Code

$ cat values?.tmp > values.log

[/edit]

RomanW

Thanks to Stefan Kögl and Kampi. Both solutions work well!

Maximilian Rupp 27. Dezember 2024 um 12:04