gcat: A cat implementation in Go

gcat is a custom implementation of the cat tool in unix-based systems. This tool covers the basic functionality of the cat command. Basically, it concatenates the input file contents and prints to stdout. It also has the ability to read from stdin.

Running the Application

• first run make build
  • this will produce an executable binary file named gcat.
• gcat can take upto two flags, these are
  • -n to print line number in front of each line
  • -b to print line number only in front of non blank lines
  • -b has more priority than -n
• gcat takes filenames separated by commas
  • if a file path is not found, it throws a file not found error.
  • a special filename is -, which means take input from stdin.

Example commands

• ./gcat test.txt
  • prints test.txt file content.
• ./gcat test.txt -n
  • prints test.txt file content with line number.
• head -n1 test.txt | ./gcat -
  • prints input passed through the pipe from the previous command.
• ./gcat test.txt test2.txt
  • concatenates test.txt & test2.txt file contents and prints it.
• sed G test.txt | ./gcat -n | head -n4
  • sed G inserts a blank line after each line in test.txt.
  • processes input passed through the pipe from the previous command and passes the output through a pipe.
  • head -n4 prints first 4 lines from the pipe.
• sed G test.txt | ./gcat -b | head -n5
  • sed G inserts a blank line after each line in test.txt.
  • processes input passed through the pipe from the previous command and passes the output through a pipe.
  • head -n5 prints first 5 lines from the pipe.

Installing the Application

• just run './install.sh' and it will automatically install the application.
• make sure, you have built the application make build before.