将脚本从Unix移动到linux bash

Question

I have a script that I'm moving from a Solaris 11.3 environment to Oracle Linux 6.9 (used for exporting databases). After updating various variables and paths the script runs correctly except for one section.

What it's supposed to do is check the target directory for other exports and delete those in excess of the indicated keep setting (in this case it's 1). When the 'cleanup' section of the script runs it's properly identifying the files, but not removing them, indicating 'binary operator expected'.

The following is the section of the script that isn't working correctly:

FILE_MASK="${ORACLE_SID}_*.dmp.gz" 
counter=0
if [[ -f ${EXP_DIR}/${FILE_MASK} ]]; then
  #
  # count the files (don't use ls command because it has a limit)
  #
  for CNT in $EXP_DIR/$FILE_MASK
  do
    counter=`expr $counter + 1`
  done
  count=`expr $counter - $KEEP_FILES + 1`
  #
  counter=0
  for I in $EXP_DIR/$FILE_MASK
  do
    counter=`expr $counter + 1`
    FILE_NAME=`basename $I`
    echo "${JOBNAME_SHORT}:  File = ${EXP_DIR}/${FILE_NAME}"
    if [[ ${counter} -lt ${count} ]] ; then
      echo "${JOBNAME_SHORT}:    Removing file."
      rm ${EXP_DIR}/${FILE_NAME}
    fi
  done

The error returned is:

/home/oracle/scripts/oraexpdp.sh: line 241: [: /u07/exports/xxxxxxxx/xxxxxxxx_2018111413.dmp.gz: binary operator expected

Line 241 of the script is the line starting with 'if' above.

In searching for a fix there was a reference to using double-bracketing ([[ ]]) with bash, and that still returns the same error. What do I need to tweak to get this working correctly?

Many Thanks!

Harvey

Answer 1

[[ -f ${EXP_DIR}/${FILE_MASK} ]] is going to give a group of files because of wild card bash substitution, so wont evaluate that a file exists.

In the case where there are no matching files ${EXP_DIR}/${FILE_MASK} will be wildcard string still.

Assuming that KEEP_FILES will always be 1 or more, you could probably just remove the if [[ -f ${EXP_DIR}/${FILE_MASK} ]] as in the case of no files, it wouldn't delete anything, as there would be just the wildcard name,

in the case of multiple files, it will behave as normal.