Getting the current directory:
$ pwd
To find some executable:
$ where perl
C:\cygwin64\bin\perl.exe
$ which perl
/usr/bin/perl
Viewing the whole content of the file:
$ cat /bin/man2html
Viewing only the first line of the file:
$ head -n 1 file.txt
Viewing only the last line of the file:
$ tail -n 1 file.txt
Editing file:
$ vi /bin/man2html
Initially, vi opens in command mode.
i - to enter edit (insert) mode
ESC - to exit edit mode
:wq - write and quit
:q! - quit without saving changes
