Viewing File Contents

• cat

  • Concatenates two files together, then prints content to STDOUT.

  • Colloquially, it's used to print out the contents of a single file.

# Start in ~/unixclass
cd ~/unixclass

cat arrayDat.txt

• head

  • By default, prints the first 10 lines of a file to STDOUT.

  • You can pass the -n flag to specify the number of lines to print.

# Start in ~/unixclass
cd ~/unixclass

# Print the first 10 lines of arrayDat.txt
head arrayDat.txt

# Print the first 5 lines of arrayDat.txt
head -n 5 arrayDat.txt

• tail

  • By default, prints the last 10 lines of a file to STDOUT.

  • You can pass the -n flag to specify the number of lines to print.

# Start in ~/unixclass
cd ~/unixclass

# Print the last 10 lines of arrayDat.txt
tail arrayDat.txt

# Print the last 5 lines of arrayDat.txt
tail -n 5 arrayDat.txt

• less

  • Lets you page through a long file or stream of text a.k.a. you can scroll.

  • Exit by pressing q

# Start in ~/unixclass
cd ~/unixclass

# Scroll through the contents of arrayDat.txt
less arrayDat.txt