First, I should say that the easiest way to do this is to use the prename or rename commands. On Ubuntu, OSX (Homebrew package rename, MacPorts package p5-file-rename), or other systems with perl rename (prename): rename s/0000/000/ F0000* or on systems with rename from util-linux-ng, such as RHEL: rename 0000 000 F0000* That’s a lot … Read more
You can sort then uniq: $ sort -u input.txt Or use awk: $ awk ‘!a[$0]++’ input.txt
Does your find have the -mmin option? That can let you test the number of mins since last modification: find $LOCATION -name $REQUIRED_FILES -type f -mmin +360 -delete Or maybe look at using tmpwatch to do the same job. phjr also recommended tmpreaper in the comments.
You can use one-line heredoc cat <<< “This is coming from the stdin” the above is the same as cat <<EOF This is coming from the stdin EOF or you can redirect output from a command, like diff <(ls /bin) <(ls /usr/bin) or you can read as while read line do echo =$line= done < … Read more
The short answer: echo “some data for the file” >> fileName However, echo doesn’t deal with end of line characters (EOFs) in an ideal way. So, if you’re gonna append more than one line, do it with printf: printf “some data for the file\nAnd a new line” >> fileName The >> and > operators are … Read more
Not the greatest, but this should work: sed -i ‘Ns/.*/replacement-line/’ file.txt where N should be replaced by your target line number. This replaces the line in the original file. To save the changed text in a different file, drop the -i option: sed ‘Ns/.*/replacement-line/’ file.txt > new_file.txt
Using existing file: paste -sd+ infile | bc Using stdin: <cmd> | paste -sd+ | bc Edit: With some paste implementations you need to be more explicit when reading from stdin: <cmd> | paste -sd+ – | bc Options used: -s (serial) – merges all the lines into a single line -d – use a … Read more
Is there a TRY CATCH command in Bash? No. Bash doesn’t have as many luxuries as one can find in many programming languages. There is no try/catch in bash; however, one can achieve similar behavior using && or ||. Using ||: if command1 fails then command2 runs as follows command1 || command2 Similarly, using &&, … Read more
If you want to have your arguments C style (array of arguments + number of arguments) you can use $@ and $#. $# gives you the number of arguments. $@ gives you all arguments. You can turn this into an array by args=(“$@”). So for example: args=(“$@”) echo $# arguments passed echo ${args[0]} ${args[1]} ${args[2]} … Read more
As you know, a dollar sign marks a variable. You have to take it into account when you are typing it. You can escape the dollar ./dd.sh “sample\$name.mp4” or just type it with single quotes ./dd.sh ‘sample$name.mp4’ To check if there is a dollar sign in a variable, do [[ $variable == *\$* ]] && … Read more