linux.txt

*Linux*

Crontab
    Sytanx:
    *minute hour day-month month day-week CMD*
    1 \* \* \* \* $ cmd # runs every minute

Extracting archives
    *$ tar xvfj test.tar.bz2*
    *$ tar zxvf test.tar.gz*
    *$ tar zxvf test.tar*
    *$ gzip -d test.gz*
    *$ unzip test.zip*
    *$ zcat rockyou.txt.gz > rockyou.txt*

Compressing archives
    *$ tar -zcvf test.tar test*
    *$ gzip test*
    *$ zip -9 test.zip test*
    *$ zip -r test.zip test/*


Copy files remotely
    *$ scp /path/to/local/file.txt user@targetIP:/path/to/share # local to remote*
    *$ scp -r user@targetIP:/path/to/share /local/share # remote to local*
    *$ cat ~/.ssh/id_rsa.pub | ssh user@targetIP 'cat >> .ssh/authorized_keys'*

File Permissions
    t rwx rwx rwx     type / owner / group / world
    Type is directory (d) or file (-).

    read    (r)     4
    write   (w)     2
    execute (e)     1

    chmod 755 test.sh                  Make a file executable
    find . -name "*.php" -type f -exec chmod 755 {} \;

Finding Files
    Update the database of file names on the system
    *$ updatedb*
    Reads the database and shows the location of a file
    *$ locate file*
    Show the path where the app is executed from
    *$ which app*
    Show all the files that start with sbd
    *$ find / -name sbd**
    Show all world readable directories
    *$ find / -perm -o+w -type d*
    Show all world executable directories
    *$ find / -perm -o+e -type d*

Searching within files
    Search for the pattern xxx in a fil
    *$ grep xxx file*
    Search recursively for a pattern in a director
    *$ grep -r*
    Search for a pattern in a zip fil
    *$ zgrep*

Troubleshoot broken dependencies
    Show referenced shared libraries and its resolution
    *$ ldd binary*

Others
    Import CA in java store
    *sudo keytool -import -alias foo -trustcacerts -keystore cacerts -file cacert.der*