Implement a simple shell in C that supports the following commands:

$1.$ echo $-$ print a string to the console

myshell$>$ echo

$2.$ cat $-$ print the contents of a file to the console

myshell$>$ cat

$3.$ grep $-$ search for a pattern in a file

myshell$>$ grep

:

Example:

# Contents of file.txt

This is a test file

This is an example file

This is a sample file

This is a test file

myshell$>$ grep test file.txt

$1$:This is a test file

$4$:This is a test file

$4.$ head $-$ print the first n lines of a file

myshell$>$ head $-$n

Example:

# Contents of file.txt

This is a test file

This is an example file

This is a sample file

This is a test file

myshell$>$ head $-$n $2$ file.txt

This is a test file

This is an example file

$5.$ tail $-$ print the last n lines of a file

myshell$>$ tail $-$n

Example:

# Contents of file.txt

This is a test file

This is an example file

This is a sample file

This is a test file

myshell$>$ tail $-$n $2$ file.txt

This is a sample file

This is a test file

$6.$ wc $-$ print the number of lines, words, and characters in a file

myshell$>$ wc

Example:

# Contents of file.txt

This is a test file

This is an example file

This is a sample file

This is a test file

myshell$>$ wc file.txt

$42086$ file.txt

$7.$ touch $-$ create a new empty file

myshell$>$ touch

$8.$ Pipes $(|)-$ support the use of pipes to chain commands together

myshell$>$ ls $|$ wc

Explaining the above example:

$-$ ls lists the contents of the current directory

$-$ wc counts the number of characters, words, and lines in the output of ls

$-$ The output of ls is piped to the input of wc and not to the console.

$-$ The output of wc is printed to the console as the result of the command

Example $2$:

# Contents of file.txt

This is a test file

This is an example file

This is a sample file

This is a test file

myshell$>$ cat file.txt $|$ grep test $|$ wc

$2$

Explaining the above example:

$-$cat file.txt prints the contents of file.txt to the console.

$-$grep test searches for the pattern test in the output of cat file.txt

$-$wc counts the number of characters, words, and lines in the output of grep test

$-$The output of cat file.txt is piped to the input of grep test and not to the console.

$-$The output of grep test is piped to the input of wc and not to the console.

$-$The output of wc is printed to the console as the result of the command

$-$The result of the command is the number of lines in file.txt that contain the pattern test

$9.$ Redirection $(>)-$ support the use of redirection to write the output of a command to a file

myshell$>$ ls $>$ files.txt

Explaining the above example:

$-$ls lists the contents of the current directory

$-$The output of ls is written to the file files.txt and not to the console

Example $3$:

myshell$>$ echo "Hello, World!" $>$ hello.txt

Explaining the above example:

$-$The output of echo "Hello, World!" is written to the file hello.txt and not to the console

$-$The file hello.txt is created if it does not exist, and overwritten if it does exist

Note that the head and tail commands should support the $-$n flag to specify the number of lines to print. If the $-$n flag is not provided, the default number of lines to print should be $10.$