>> echo

echo

echo is used to print the text/string which are entered following the 'echo'

echo  Sea is blue.  press ENTER

Output:

Sea is blue.

echo with curly brackets{}

echo {a..d}  press ENTER
Output:
a b c d

echo {1..5}  press ENTER
Output:
1 2 3 4 5

echo {a..d}z  press ENTER
Output
az bz cz dz

echo a{a..d}1  press ENTER
Output:
aa1 ab1 ac1 ad1

echo  $variable

let's save a value in a variable

x = 10   press ENTER

echo  x  is having  the value  $x   press ENTER

Output:

x is having the value 10

height=10ft  press ENTER

echo The bridge is $height tall.   press ENTER

Output

The bridge is 10ft tall.

\n  (new line)

Use  echo  and  "\n"  together with  "-e"  to  break the string/texts to new line.

echo  -e  "Sea is blue. \nSun is our star \nand Earth  is our  home."   ---Press ENTER

Output:

Sea is blue.

Sun is our star

and Earth  is our  home.

If you need more space between the lines , then  add more "\n" like  "\n \n " , "\n \n \n "

echo  -e  "Sea is blue. \n\nSun is our star \n\n \nand Earth  is our  home."   ---Press ENTER

Output:

Sea is blue.

Sun is our star

and Earth  is our  home.

\t  (tab)

Use  echo  and  "\t"  together with  "-e"  to add tab space in string.

echo  -e  "Sea is blue. \tSun is our star \tand Earth  is o\tur  home."   ---Press ENTER

Output:

Sea is blue.    Sun is our star         and Earth  is o ur  home.

If you need more space add more \t  like  \t\t  , \t\t\t

echo  -e  "Sea is blue. \t\tSun is our star \t\t\tand Earth  is o\t\tur  home."   ---Press ENTER

Output:

Sea is blue.            Sun is our star                         and Earth  is o         ur  home.

\b (back space)

Use  echo  and  "\b"  together with  "-e"  to remove spaces between  the text where ever required.

echo  -e  "Sea is blue. \bSun is \bour star \band Earth  is our  home."   ---Press ENTER

Output:

Sea is blue.Sun isour starand Earth  is our  home.

\r  ( removes text  before  " \r " )

echo  -e  "Sea is blue. \rSun is our star and Earth  is our  home."

Output:

Sun is our star and Earth  is our  home.

echo * (echo SPACE *)---This is similar to "ls"

echo *  --- This will list all the files and folders in present directory.

echo *.extension --- to list all the file with the given extension.

echo *.txt ---  This will list all the .txt files present in the current directory.

">" use this operator with echo to redirect the output to a file.

echo string/text>fileName

echo  Sun  is our star.>file1  --- The string/text  "Sun is our star." is saved in the file and we can not see this text as standard output , ie, to see this text you need to open the file1.

> if file1 does not exist already, it creates new file file1 with the redirected text in the file.

>if file1 already exists , the redirected text will replace the original content of the file.

">>" use this operator with echo to redirect the output to a file , appending that file.

echo string/text>>fileName

echo  Moon is a satellite.>>file1  --- The string/text  " Moon is a satellite." is saved in the file and we can not see this text as standard output , ie, to see this text you need to open the file1.

> if file1 does not exist already, it creates new file file1 with the redirected text in the file.

>if file1 already exists , the redirected text will be appended to the file file1.