Bash ​

Random bash tips and tricks to (try to) use Bash properly and efficiently...

Loops ​

To iterate over a sequence of numbers:

1. With a know fixed upper limit

   bash

   for i in {1..5}; do
       echo $i;
   done

2. With a possibly unknown upper limit

   bash

   END=5
   for i in $(seq 1 $END); do
       echo $i;
   done

3. If seq can't be used

   bash

   END=5
   for ((i=1;i<=END;i++)); do
       echo $i
   done

[ref]

Tar archives manipulation ​

Listing content ​

To list the content of an archive without extracting, use the --list/-t option:

tar --list --file <my-archive.tar>
tar -tf <my-archive.tar>

Creating archives ​

To create an archive, use the --create/-c option:

tar --create --file <my-archive.tar> <file1> <dir1>
tar -cf <my-archive.tar> <file1> <dir1>

Extracting the content ​

To extract the files of an archive, use the --extract/-x option:

tar --extract --file <my-archive.tar>
tar -xf <my-archive.tar>

This will extract all the content of the archive in the current folder

To extract in a different folder:

tar -xf <my-archive.tar> -C </my/folder>

Note: the folder needs to exists first.

To extract only specific files:

tar -xf <my-archive.tar> <file1> <dir1>

Note: The name of the files and/or dirs to extract must be the same as listed using the --list option.

Other ​

To manipulate .tar.gz archives, add the -z option to al commands.

By default, all commands will read from stdin or write to stdout, allowing incoming and outgoing piping. To read to or from an existing archive, use the --file/-f option.