In a rather large project, I run into the following problem: while calculating the correct command in a bash script, I don't manage to make the script respect the double quote necessary for single arguments with a blank.
$ ./testo "two three"
ls -l "two three_DD_FF" # <- Why does it look for two files HERE??
ls: cannot access '"two': No such file or directory
ls: cannot access 'three_DD_FF"': No such file or directory
"two three" is the single argument.
With two_three my code works, as to be expected:
$ ./testo two_three
ls -l "two_three_DD_FF"
ls: cannot access '"two_three_DD_FF"': No such file or directory
And this is the basic generic code that I could come up with:
#!/usr/bin/bash
cmd="ls -l"
trio=""'"'"${1}_DD"
trio="${cmd} ${trio}_FF"'"'""
echo ${trio}
${trio}
(I didn't find a less strange method than the one above for the strangely looking strong quote, but that is not my main concern here.)
What I don't understand is the problem in execution:
ls -l "two three_DD_FF"
in the line above still leads to searching for two files, despite of the double quotes; while the same line on the command prompt does a job as intended (that is, searching for file "two three_DD_FF":
$ ls -l "two three_DD_FF"
-rw-rw-r-- 1 myhome me 0 Aug 27 13:09 'two three_DD_FF'
That is, the line echo ${trio} shows a correct command (when executed on the command line, at least; while the same command, when executed from within a script, fails. It fails to respect the double quotes for the file name to be searched.
My questions:
My recommendation: work with arrays:
#!/usr/bin/env bash
cmd=(ls -l)
trio=( "${cmd[@]}" "${1}_DD_FF" )
"${trio[@]}"