Unix/Linux useful commands

# cat -A file.txt 
foo$
bar$

# file file.txt 
file: ASCII text

unix2dos

# unix2dos file.txt 
unix2dos: converting file file.txt to DOS format...

# file file.txt 
file.txt: ASCII text, with CRLF line terminators

# cat -A file.txt 
foo^M$
bar^M$

# cat -v file.txt 
foo^M
bar^M

dos2unix

# dos2unix file.txt 
dos2unix: converting file file.txt to Unix format...

# file file.txt 
file.txt: ASCII text

# cat -A file.txt 
foo$
bar$

# cat -v file.txt 
foo
bar

pgrep

pgrep nginx # will list all processes whose commands match nginx

pgrep -f nginx # will list all processes whose entire command lines match nginx

pgrep -x nginx # will list all processes whose commands exactly match nginx