1. tty - reveals the current terminal
2. whoami - reveals the currently logged-in user
3. which - reveals where in the search path a program is located
4. echo - prints to the screen
a. echo $PATH - dumps the current path to STDOUT
b. echo $PWD - dumps ths contents of the $PWD variable
c. echo $OLDPWD - dumps the most recently visited directory
5. clear - clears the screen or terminal
6. history - reveals your command history
a. command history is maintained on a per-user basis via:
~/.sh_history
~ = users's $HOME directory
7. pwd - prints the working directory
8. cd - changes directory to desired directory
a. 'cd ' with no options changes to the $HOME directory
b. 'cd ~' changes to the $HOME directory
c. 'cd /' changes to the root of the file system
d. 'cd ..' changes us one-level up in the directory tree
e. 'cd ../..' changes us two-levels up in the directory tree
9. ls - lists files and directories
a. ls / - lists the contents of the '/' mount point
b. ls -l - lists the contents of a directory in long format:
Includes: permissions, links, ownership, size, date, name
c. ls -ld /etc - lists properties of the directory '/etc', NOT the contents of '/etc'
d. ls -ltr - sorts chronologically from older to newer (bottom)
e. ls -a - reveals hidden files. e.g. '.sh_history'
Note: files/directories prefixed with '.' are hidden. e.g. '.sh_history'
10. cat - catenates files
a. cat 123.txt - dumps the contents of '123.txt' to STDOUT
b. cat 123.txt 456.txt dumps both files to STDOUT
c. cat 123.txt 456.txt > 123456.txt - creates new catenated file
11. mkdir - creates a new directory
a. mkdir test - creates a 'test' directory
12. cp - copies files
a. cp 123.txt test/
13. mv - moves files
a. mv 123456.txt test/ - moves the file, preserving timestamp
14. rm - removes files/directories
a. rm 123.txt
b. rm -rf 456.txt - removes recursively and enforces
15. touch - creates blank file/updates timestamp
a. touch test.txt - will create a zero-byte file, if it doesn't exist
b. touch 123456.txt - will update the timestamp
c. touch -t 201003221530 123456.txt - changes timestamp
16. stat - reveals statistics of files
a. stat 123456.txt - reveals full attributes of the file
17. find - finds files using search patterns
a. find / -name 'fstab'
Note: 'find' can search for fields returned by the 'stat' command
18. alias - returns/sets aliases for commands
a. alias - dumps current aliases
b. alias copy='cp'
###Unix Redirection & Pipes###
Features:
1. Ability to control input and output
Input redirection '<':
1. cat < 123.txt
Note: Use input redirection when program does NOT default to file as input
Output redirection '>':
1. cat 123.txt > onetwothree.txt
Note: Default nature is to:
1. Clobber the target file
2. Populate with information from input stream
Append redirection '>>':
1. cat 123.txt >> numbers.txt - creates 'numbers.txt' if it doesn't exist, or appends if it does
2. cat 456.txt >> numbers.txt
Pipes '|':
Features: Connects the output stream of one command to the input stream of a subsequent command
1. cat 123.txt | sort
2. cat 456.txt 123.txt | sort
3. cat 456.txt 123.txt | sort | grep 3
###Command Chaining###
Features:
1. Permits the execution of multiple commands in sequence
2. Also permits execution based on the success or failure of a previous command
1. cat 123.txt ; ls -l - this runs first command, then second command without regards for exit status of the first command
2. cat 123.txt && ls -l - this runs second command, if first command is successful
3. cat 1234.txt && ls -l
4. cat 123.txt || ls -l - this runs second command, if first command fails
20. more|less - paginators, which display text one-page @ a time
1. more /etc/fstab
2. less 1thousand.txt
21. seq - echoes a sequence of numbers
a. seq 1000 > 1thousand.txt - creates a file with numbers 1-1000
22. su - switches users
a. su - with no options attempts to log in as 'root'
23. head - displays opening lines of text files
a. head /var/log/messages
24. tail - displays the closing lines of text files
a. tail /var/log/messages
25. wc - counts words and optionally lines of text files
a. wc -l /var/log/messages
b. wc -l 123.txt
26. file - determines file type
a. file /var/log/messages
###Tar, Gzip###
Features:
1. Compression utility (gzip)
2. File roller (the ability to represent many files as one - tar)
Gzip:
Includes:
1. gzip - compresses/decompresses files
2. gunzip - decompresses gzip files
Tasks:
1. compress '1million.txt' file using gzip
a. gzip -c 1million.txt > 1million.txt.gz
Note: gzip auto-dumps to STDOUT, by default
b. gzip -l 1million.txt.gz - returns status information
c. gunzip 1million.txt.gz - dumps to file, and removes compressed version
d. gzip -d 1million.txt.gz
e. zcat 1million.txt.gz - dumps the contents to STDOUT
f. less 1million.txt.gzip - dumps the contents of gzip files to STDOUT
Tar :
1. tar -cvf filename.tar path/ - creates a non-compressed archive
2. tar -cvf 1million.txt.tar 1million.txt
###GREP###
Features:
1. The ability to parse lines based on text and/or RegExes
2. Post-processor
3. Searches case-sensitively, by default
4. Searches for the text anywhere on the line
1. grep 'linux' grep1.txt
2. grep -i 'linux' grep1.txt - case-insensitive search
3. grep '^linux' grep1.txt - uses '^' anchor to anchor searches at the beginning of lines
4. grep -i '^linux' grep1.txt
5. grep -i 'linux$' grep1.txt - uses '$' anchor to anchor searches at the end of lines
Note: Anchors are RegEx characters (meta-characters). They're used to match at the beginning and end of lines
6. grep '[0-9]' grep1.txt - returns lines containing at least 1 number
7. grep '[a-z]' grep1.txt
8. grep -v sshd messages - performs and inverted search (all but 'sshd' entries will be returned)
9. grep -v sshd messages | grep -v gconfd
2. whoami - reveals the currently logged-in user
3. which - reveals where in the search path a program is located
4. echo - prints to the screen
a. echo $PATH - dumps the current path to STDOUT
b. echo $PWD - dumps ths contents of the $PWD variable
c. echo $OLDPWD - dumps the most recently visited directory
5. clear - clears the screen or terminal
6. history - reveals your command history
a. command history is maintained on a per-user basis via:
~/.sh_history
~ = users's $HOME directory
7. pwd - prints the working directory
8. cd - changes directory to desired directory
a. 'cd ' with no options changes to the $HOME directory
b. 'cd ~' changes to the $HOME directory
c. 'cd /' changes to the root of the file system
d. 'cd ..' changes us one-level up in the directory tree
e. 'cd ../..' changes us two-levels up in the directory tree
9. ls - lists files and directories
a. ls / - lists the contents of the '/' mount point
b. ls -l - lists the contents of a directory in long format:
Includes: permissions, links, ownership, size, date, name
c. ls -ld /etc - lists properties of the directory '/etc', NOT the contents of '/etc'
d. ls -ltr - sorts chronologically from older to newer (bottom)
e. ls -a - reveals hidden files. e.g. '.sh_history'
Note: files/directories prefixed with '.' are hidden. e.g. '.sh_history'
10. cat - catenates files
a. cat 123.txt - dumps the contents of '123.txt' to STDOUT
b. cat 123.txt 456.txt dumps both files to STDOUT
c. cat 123.txt 456.txt > 123456.txt - creates new catenated file
11. mkdir - creates a new directory
a. mkdir test - creates a 'test' directory
12. cp - copies files
a. cp 123.txt test/
13. mv - moves files
a. mv 123456.txt test/ - moves the file, preserving timestamp
14. rm - removes files/directories
a. rm 123.txt
b. rm -rf 456.txt - removes recursively and enforces
15. touch - creates blank file/updates timestamp
a. touch test.txt - will create a zero-byte file, if it doesn't exist
b. touch 123456.txt - will update the timestamp
c. touch -t 201003221530 123456.txt - changes timestamp
16. stat - reveals statistics of files
a. stat 123456.txt - reveals full attributes of the file
17. find - finds files using search patterns
a. find / -name 'fstab'
Note: 'find' can search for fields returned by the 'stat' command
18. alias - returns/sets aliases for commands
a. alias - dumps current aliases
b. alias copy='cp'
###Unix Redirection & Pipes###
Features:
1. Ability to control input and output
Input redirection '<':
1. cat < 123.txt
Note: Use input redirection when program does NOT default to file as input
Output redirection '>':
1. cat 123.txt > onetwothree.txt
Note: Default nature is to:
1. Clobber the target file
2. Populate with information from input stream
Append redirection '>>':
1. cat 123.txt >> numbers.txt - creates 'numbers.txt' if it doesn't exist, or appends if it does
2. cat 456.txt >> numbers.txt
Pipes '|':
Features: Connects the output stream of one command to the input stream of a subsequent command
1. cat 123.txt | sort
2. cat 456.txt 123.txt | sort
3. cat 456.txt 123.txt | sort | grep 3
###Command Chaining###
Features:
1. Permits the execution of multiple commands in sequence
2. Also permits execution based on the success or failure of a previous command
1. cat 123.txt ; ls -l - this runs first command, then second command without regards for exit status of the first command
2. cat 123.txt && ls -l - this runs second command, if first command is successful
3. cat 1234.txt && ls -l
4. cat 123.txt || ls -l - this runs second command, if first command fails
20. more|less - paginators, which display text one-page @ a time
1. more /etc/fstab
2. less 1thousand.txt
21. seq - echoes a sequence of numbers
a. seq 1000 > 1thousand.txt - creates a file with numbers 1-1000
22. su - switches users
a. su - with no options attempts to log in as 'root'
23. head - displays opening lines of text files
a. head /var/log/messages
24. tail - displays the closing lines of text files
a. tail /var/log/messages
25. wc - counts words and optionally lines of text files
a. wc -l /var/log/messages
b. wc -l 123.txt
26. file - determines file type
a. file /var/log/messages
###Tar, Gzip###
Features:
1. Compression utility (gzip)
2. File roller (the ability to represent many files as one - tar)
Gzip:
Includes:
1. gzip - compresses/decompresses files
2. gunzip - decompresses gzip files
Tasks:
1. compress '1million.txt' file using gzip
a. gzip -c 1million.txt > 1million.txt.gz
Note: gzip auto-dumps to STDOUT, by default
b. gzip -l 1million.txt.gz - returns status information
c. gunzip 1million.txt.gz - dumps to file, and removes compressed version
d. gzip -d 1million.txt.gz
e. zcat 1million.txt.gz - dumps the contents to STDOUT
f. less 1million.txt.gzip - dumps the contents of gzip files to STDOUT
Tar :
1. tar -cvf filename.tar path/ - creates a non-compressed archive
2. tar -cvf 1million.txt.tar 1million.txt
###GREP###
Features:
1. The ability to parse lines based on text and/or RegExes
2. Post-processor
3. Searches case-sensitively, by default
4. Searches for the text anywhere on the line
1. grep 'linux' grep1.txt
2. grep -i 'linux' grep1.txt - case-insensitive search
3. grep '^linux' grep1.txt - uses '^' anchor to anchor searches at the beginning of lines
4. grep -i '^linux' grep1.txt
5. grep -i 'linux$' grep1.txt - uses '$' anchor to anchor searches at the end of lines
Note: Anchors are RegEx characters (meta-characters). They're used to match at the beginning and end of lines
6. grep '[0-9]' grep1.txt - returns lines containing at least 1 number
7. grep '[a-z]' grep1.txt
8. grep -v sshd messages - performs and inverted search (all but 'sshd' entries will be returned)
9. grep -v sshd messages | grep -v gconfd
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