3.12. Backticks (`...`)

Commands within backticks generate command line text.

The output of commands within backticks can be used as arguments to another command or to load a variable.

rm `cat filename` # "filename" contains a list of files to delete. textfile_listing=`ls *.txt` # Variable contains names of all *.txt files in current working directory. echo $textfile_listing

z=`expr $z + 3`

Note that this particular use of backticks has been superseded by double parentheses $((...)) or the very convenient let construction.

z=$(($z+3)) let z=z+3 let "z += 3" #If quotes, then spaces and special operators allowed.

All these are equivalent. You may use whichever one "rings your chimes".