Removing all spaces, tabs, newlines, etc from a variable?

Question

This is the error I am getting and it's failing because of a variable whose value is supposed to be 2 (I am getting this using a select * from tabel). I am getting spaces in that variable.

+ 0 != 
         2
./setjobs[19]: 0:  not found.

How do I remove all those spaces or a newline from that variable? Can tr, sed, or anything help?

This what I am doing:

set_jobs_count=$(echo  "set heading off;
      select count(*) from oppar_db
      where ( oppar_db_job_name, oppar_db_job_rec ) in ($var) ;" | \
  sqlplus -s ${OP_ORA_USER}/${OP_ORA_PASS}@$OPERATIONAL_DB_NAME)

---

This works as suggested:

| sed 's/[[:space:]]//g'

But I still obtain a value like :

  set_jobs_count=
  2

Answer 1

You can use tr, as in tr -d '\040\011\012\015', which will remove spaces, tabs, carriage returns and newlines.

Answer 2

In ksh, bash or zsh:

set_jobs_count=…
set_jobs_count=${set_jobs_count//[[:space:]]/}

In any shell, you can remove leading and trailing whitespace and normalize all intermediate whitespace to a single space like this:

set +f
set -- $set_jobs_count
set_jobs_count=$*
set -f

set +f turns off globbing; if you know that the data contains none of the characters \[?*, you can omit it.