22) $ x=paul

23) $ echo  “ $x \nlikes \necho”

• It will also print the x value

Find command

Find command is used to search and locate the list of files and directories based on conditions you specify for files that match the arguments. Find can be used in a variety of conditions like you can find files by permissions, users, groups, file type, date, size, and other possible criteria

Note: (.) is for the current directory

24.) $ find . -name file_name / dir._name

    Used to find the file/directory in the current directory

25.) $ find . -type f/d -empty

    To find the empty dir/ file     ** f for file & d for directory

26) $ find . -mtime  -1

   To find the file/directory which is made within one day

27) $ find . -mtime  +1

   To find the file/dir. which was made 1 day ago

28) $find . -mmin 1

   To find the file/dir. which was made 1 min ago/  To find the file/dir which is made within 1 min.

29) $ find ./ type d/f -name file/dir

   To find the directory / file

        ** f for file and d for directory

30) $ find . *.extension

   To find the all file which is with the assigned extension.

        ** here there is no .jpg file available

31) $ find dir.name

   To show all the files and directories

32) $ find -iname “char*”

   To find all the files and dir. starting with the f* and -i not including case sensitivity

33) $ find ./ -type f/d -iname “f*”

   To find file or directory with disable case sensitivity and listing files / dir with f*

34) $ find . -size +0

   This will show the file presented in the current directory which is more than 0 mega byte.

         ** G = GB

         ** K= KB

35) $ du -sh file/dir

    It will give the size of the file or directory in KB

Vi editor

After $ vi d1 write the text by pressing (I for Insert )click→ Esc→ shift + :→ wq → Enter

GREP – Global Regular Expression Print

“It allow us to search text within files in a system”

36) $ grep [binary digit] file_name

   It will search the binary number which are inserted in the square bracket.

37) $ grep -w “string” file_name

   It will only show the valid text inserted in the inverted commas.

38) $ grep -i “string” file_name

   It is non-case sensitive command (  -i )

39) $ grep “string” file_name

   Show all the matching text.

40) $grep -win “string” file_name

   Show at which line the text resides.

41) $ grep -win -B 4 “string” file_name

  Show the 4 line before the inserted text.

Show the 2 lines above and below the text.

 

Show the 2 lines after the text

42) $ grep -win -A2 ‘String” d1

43) $ grep -winr “string” ./*

   [centos@localhost ~]$ grep -winr “cat” ./*

   It will show all the files and folders with the string.

AWK command (Aho, Weinberger and Kernighan)

 

It is just a scripting language used to it doesn’t require compilation time and it generates reports by processing file. It is beneficial for pattern searching and processing files.

Various programming concepts offered by AWK are:

     1) Output formatting

     2) Inbuilt variables

     3) Pattern matching

     4) String operations

     5) Arithmetic operations

Basic syntax

# awk options ‘selection _criteria {action }’ input-file > output-file

Awk assign some variables for each field.

→ $0 denotes the whole file

→ $1 denotes the first field

→ $2 denotes the second field

     And $3,$4,$5…..so on for every field.

Commands related AWK

 

44) # awk ‘{print $variable}’ file_name

   This command will print the field according to the variable

 

45) # awk –version

   We can also check the version of the awk.

         # awk -F: ‘{print $variable}’ filename

This will print the file without the separator (i.e. [:])

46) # echo “string” | awk ‘{$variable=”string”; print  $variable}’

    This will replace the string manish to raghav  and print the whole string.

 

47) # cat file_name | awk ‘{$variable=”string”; print $variable}’

   This command  will replace the particular string which is in field 2 and  print the whole file content.

48) # awk ‘/string/’ file_name 

   This command will show each line that contains the following word i.e.( or )

49) # awk ‘$variable==”char” {print $variable}’ file_name

   T

his will print 5th field if the field 1 value matches the value 300 in the file.

CUT command

 

The cut command basically a Unix command line utility which extracts section from each line.

Basically the cut command slices a line and extracts the text.

50) # cat -b variable file_name

     This cut command will extract the following byte (-b) from the file.

 

51) # cut -d ‘delimiter’ -f field/ranges/sequence file_name

   This command will show the following fields/ranges from the file

   if -d option is not used then it prints whole line:

52) # cut -c variable file_name

   This command will print each character from the file starting from 1st field.

53) # cut –complement -d “  “ -f variable file_name

   This command will print each field except the 3rd field

54) # echo field >> file_name

   This command will permanently add on the field at last into the file

55) # cut -d “ “ -fvariable file_name

    This command will show only the 3rd field from the file

SED command

 

It is also called stream editor, it is a powerful linux/unix utility tool used for text manipulation, finding, deletion, saving permanently, etc.

s: means substitute

g: means globally

56) # sed ‘s/string1/string2/g’ file_name

   This command will change the string1 to string2

57) # sed /\bstring1\b/string2/g’ file_name

   This will replace the exact matching word list into raghav in the file.

58) # sed ‘s/^string1/string2/g’ file_name

   This command will change the value which ends with $ sign in the file.

Deletion 

 

59) # sed ‘/word/d’ file_name

  This command will delete the particular line which consists of the particular word.

   ‘d’ denotes the delete.

Saving permanently to the file

 

60) # sed -i ‘s/char1/char2/g’ file_name

-i → use this -i ,if you want to change or modify directly to the file

        This -i can be used at the above sed commands this will permanently save every modification in the file.

 

Conclusion: By following this tutorial you will get the basic understanding of Linux commands