Kickin' It Old School with the Command Line

Beginners: Become comfortable with moving around, setting directory and file permissions, copying directories and files, moving directories and files, access servers with ssh, and more.

Intermediate: Expand your knowledge with tips for searching with grep, sharing sessions with screen, piping output, and more.

Advanced: Contribute with some of the voodoo that you do, and assist others during the workshop section.

Transcript

1. Kickin’ It Old School
   by
   Rachel Baker
   with the Command Line
   

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2. Goals
   1. Help beginners become more comfortable with using the
   command line tools.

   2. Expand the knowledge of intermediate command line users.

   3. Engage everyone in an educational (hopefully) workshop
   exercise of adding a user to a remote server, connecting to
   the remote server with your SSH key, and pairing with
   screen.

   4. Guilting other senior engineers into helping anyone stuck
   during the workshop portion.
   

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3. Essentials
   

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4. Little Help
   pwd Display current directory path.

   pwd : print working directory
   man : format and display manual pages
   man cd Display manual for cd command.

   man man Display manual for the man command.
   

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5. Moving Around
   cd : change working directory
   cd .. Move up one directory.

   cd ~ Move to the home directory.

   cd - Move to your last directory location.

   cd /usr/bin Move into the /usr/bin directory.

   cd / Move into the root directory.
   !
   !
   

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6. Create folders
   mkdir wp Create a directory named “wp” within my current
   working directory.

   mkdir ~/wp Create a directory named “wp” within my home
   directory.
   mkdir : make a directory
   

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7. touch : create a file
   touch hiphop.txt Creates the empty file (0 bytes) hiphop.txt in
   the current working directory, if the file doesn’t
   already exist.
   touch hip.sh hop.sh Creates empty files hip.sh and hop.sh in the
   current working directory, if the file doesn’t
   already exist.
   touch -m 01021200 hip.sh
   Changes access and modification time for the
   file hip.sh to January 2nd at 12:00pm of the
   current year.
   Create Files
   

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8. List Contents
   ls : list contents of a directory
   ls List contents of the current directory.

   ls -a List all contents of the current directory.

   ls ~ -h List contents of your home directory with human-
   readable file sizes.

   

   ls ~ -ahl List all contents of your home directory with
   permissions and human-readable file sizes.
   

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9. Copy Contents
   cp : copy files and directories
   cp file.txt ~ Copy file.txt in current working directory to
   home directory.
   cp -R files/ /wp Copy everything in files directory from current
   working directory into /wp directory. The files
   directory itself is not included.
   cp -R files /wp Same as above, but the files directory itself is
   included.
   cp foo.txt bar.txt Copy all contents of foo.txt file to bar.txt file.
   

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10. Move Contents
    mv : move files and directories
    mv foo.txt bar.txt Renames foo.txt in current working directory
    to bar.txt.

    mv ~/wp / Move the wp directory and its contents from
    home into root.

    mv ~/wp/* / Move the contents of the wp directory from
    home into root.
    !
    !
    

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11. Searching
    

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12. Locate Files
    find : walk a hierarchy
    find /wp -type f -name "*.php"
    Find all php files in the “wp” directory.

    find / -mmin -60 

    Find all files that were modified within the past hour.
    find / -size +50M
    Find all files that are larger than 50MB.
    find / -type d -name "wp-*"

    Find all directories that begin with “wp-“.
    find . -type f -exec chmod 644 {} ‘;’
    Find all files within the current working directory and
    change their permissions to 644.
    

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13. Search Within
    grep : prints lines that are a pattern match
    grep define /srv/wp/wp-config.php
    Find all lines that contain the string “define” in the wp-
    config.php file.

    grep -n define /srv/wp/wp-config.php

    Find all lines that contain the string “define” in the wp-
    config.php file, and display the line number.
    grep -inr Error /var/log
    Recursively find anything in in the /var/log that contains
    the string “Error” (case insensitive) and display the line
    number.
    

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14. Streams
    

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15. ls -ahl /wp > root-files.txt
    Creates a file (root-files.txt) that contains the output
    of the ls command. If the file already exists it is
    overwritten.
    Streaming Output
    > : redirect stdout to a file
    >> : redirect and append stdout to a file
    ls -ahl /wp >> root-files.txt
    Creates a file (root-files.txt) that contains the output
    of the ls command. If the file already exists the
    output is appended.
    

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16. cp ~/wp /wp > cp-output.txt 2>&1
    Creates a file (cp-output.txt) that contains the output
    or the error of the cp command. If the file already
    exists it is overwritten.
    Streaming Errors
    2>&1 : send stderr to same location as stdout
    2>> : redirect and append stderr to a file
    cp ~/wp /wp > /dev/null 2>> cp-errors.txt
    Ignore stdout from cp command, but create or append
    stderr to a file (cp-errors.txt).
    

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17. find . -type d | sed 's:[^-][^/]*/:--:g; s:^-: |:'
    Find directories within current working directory and modify the
    output stream to display a graphical tree of subdirectories.
    !
    history | awk '{print $2}' | awk 'BEGIN {FS="|"} {print $1}’| sort | uniq -
    c | sort -rn | head -10
    Get command history, sort output by second column
    (command), count the uniques, sort and display 10 most
    common results.
    Piping Output
    | : process and command chaining tool
    

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18. Workshop
    http://rachelbaker.me/tenup.html
    

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