Difference between revisions of "Centos File System Commands"
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more file.txt | more file.txt | ||
'''the less command is named for doing more than the more command (remember that “less is more,” more or less). Like the more command, the less command can browse the contents of a text file page by page by pressing the spacebar and line by line by pressing the Enter key; however, you can also use the cursor keys on the keyboard to scroll up and down the contents of the file.''' | '''the less command is named for doing more than the more command (remember that “less is more,” more or less). Like the more command, the less command can browse the contents of a text file page by page by pressing the spacebar and line by line by pressing the Enter key; however, you can also use the cursor keys on the keyboard to scroll up and down the contents of the file.''' | ||
'''Displaying the Contents of Binary Files''' | |||
string /bin/echo | more | |||
# string command piped to the more command | |||
'''od command, which displays the contents of the file in octal format (numeric base 8 format).''' | |||
od filename | head -5 | |||
# od command piped to head to display 5 lines | |||
'''Grep Command requires a minimum of two arguments, search are case sensitive''' | |||
grep "find this" filename.txt | |||
grep -i "find this" filename.txt | |||
# the -i option makes it case insensitive | |||
'''To view lines that contain the word “toe” or “the” or “tie,” you can enter the following command:''' | |||
grep "t.e" filename.txt | |||
'''To view lines that start with the word “I,” ''' | |||
grep "^i" filename.text | |||
Revision as of 21:04, 27 January 2019
File Command displays type of file
file me.text #output ASCII text
Wildcard Metacharacters
* Matches 0 or more characters in a filename ? Matches 1 character in a filename [aegh] Matches 1 character in a filename—provided this character is either an a, e, g, or h [a-e] Matches 1 character in a filename—provided this character is either an a, b, c, d, or e [!a-e] Matches 1 character in a filename—provided this character is NOT an a, b, c, d, or e
Viewing Text Files
cat -n file.txt # will display the file with line numbers tac file.text #will display the file in reverse
The head command displays the first 10 lines (including blank lines) of a text file to the terminal screen but can also take a numeric option specifying a dif- ferent number of lines to display.
head -3
tail command can be used to display the end of text files. By default, the tail command displays the final 10 lines of a file, but it can also take a numeric option specifying the number of lines to dis- play on the terminal screen
tail -3
The more command gets its name from the pg command once used on UNIX systems. The pg command displayed a text file page by page on the terminal screen, starting at the begin- ning of the file; pressing the spacebar or Enter key displays the next page, and so on.
more file.txt
the less command is named for doing more than the more command (remember that “less is more,” more or less). Like the more command, the less command can browse the contents of a text file page by page by pressing the spacebar and line by line by pressing the Enter key; however, you can also use the cursor keys on the keyboard to scroll up and down the contents of the file. Displaying the Contents of Binary Files
string /bin/echo | more # string command piped to the more command
od command, which displays the contents of the file in octal format (numeric base 8 format).
od filename | head -5 # od command piped to head to display 5 lines
Grep Command requires a minimum of two arguments, search are case sensitive
grep "find this" filename.txt grep -i "find this" filename.txt # the -i option makes it case insensitive
To view lines that contain the word “toe” or “the” or “tie,” you can enter the following command:
grep "t.e" filename.txt
To view lines that start with the word “I,”
grep "^i" filename.text