Return to Answer

This is simpler:

{ [ `wc -l < report` -eq 4 ] || exit; } 2>/dev/null 
echo " Proceed further"

Notes:

• If report exists and is 4 lines long, then wc -l report returns:

   4 report
  

  ...which -eq can't understand. Instead do wc -l < report which outputs an -eq-friendly:

   4
  

• There's no need to check if the file exists, since the redirection will do that anyway, and return the same error code.

This is simpler:

{ [ `wc -l < report` -eq 4 ] || exit; } 2>/dev/null 
echo " Proceed further"

Notes:

• If report exists and is 4 lines long, then wc -l report returns:

   4 report
  

  ...which -eq can't understand. Instead do wc -l < report which outputs an -eq-friendly:

   4
  

• There's no need to check if report exists, since the < redirection will do that anyway, and returns the same error code.

• More specific exit codes. If report does not exist, the exit code is 2. If report is 5 lines long, the exit code is 1.

This is simpler:

{ [ `wc -l < report` -eq 4 ] && echo " Proceed further"; } 2>/dev/null

Notes:

• If report exists and is 4 lines long, then wc -l report returns:

   4 report
  

  ...which -eq can't understand. Instead do wc -l < report which outputs an -eq-friendly:

   4
  

• There's no need to check if the file exists, since the redirection will do that anyway, and return the same error code.

This is simpler:

{ [ `wc -l < report` -eq 4 ] || exit; } 2>/dev/null 
echo " Proceed further"

Notes:

• If report exists and is 4 lines long, then wc -l report returns:

   4 report
  

  ...which -eq can't understand. Instead do wc -l < report which outputs an -eq-friendly:

   4
  

• There's no need to check if the file exists, since the redirection will do that anyway, and return the same error code.

This would return more specific error codes, and is simpler:

{ [ `wc -l < report` -eq 4 ] && echo " Proceed further"; } 2>/dev/null

This is simpler:

{ [ `wc -l < report` -eq 4 ] && echo " Proceed further"; } 2>/dev/null

Notes:

• If report exists and is 4 lines long, then wc -l report returns:

   4 report
  

  ...which -eq can't understand. Instead do wc -l < report which outputs an -eq-friendly:

   4
  

• There's no need to check if the file exists, since the redirection will do that anyway, and return the same error code.