cut

  • This command is used to cut each line in a file into a set of fields/bytes and specify ceratin values of them to be selected.

  • It uses one-indexing when specifying the characters/fields to select.

  • Using the -b argument

    • cat FILE | cut -b 3,4
      Prints the third and fourth characters in each line of FILE.
      Note: Don’t leave a space after the comma for the list of characters/indecies.

    • cat FILE | cut -b 3-7
      Prints the characters in range 3 to 7 in each line of FILE.
      Note: Don’t leave a space after the dash for the range of characters/indecies.
      Dropping the end index START- means to select all the characters from START till the end of the line.

  • Using the -f argument
    • cat FILE | cut -f 2
      If a delimiter isn’t specified using -d then the command uses tabs to split the fields. -f 2 selects the second field in the line (The value after the first tab in the line and before the second one)
    • cat FILE | cut -d " " -f 2
      Splits each line using spaces ` ` and selects the second value after splitting

lspci -vvv:

  • Think of it as if you say list pci which shows the different devices connected to the motherboard

lscpu:

  • Similar idea as lspci but for the CPU.
  • head -n -1 FILENAME truncates the last line from the file.

tail

  • tail -n +2 FILENAME truncates the first line from the file.

df

  • df -h shows the usage of the different hard drive partitions
  • df -sh DIR_NAME shows the total size (summary, thus the -s) of a specific directory DIR_NAME