what is "|" in Ubuntu or Linux in general

Question

example :

diskFreeSpace="$(df | grep -v -E 'Filesystem|udev|tmpfs|Home|/dev/sr1|/dev/sr0' | awk '{ print $5-1+1}')"

and hope if you understand what is this command u help me

But some of those `|` (called "pipes") are in a regular expression, so see also https://stackoverflow.com/q/4736/3001761. — jonrsharpe, Jul 03 '18 at 08:38

score -1 · Accepted Answer · answered Jul 03 '18 at 08:42

-1

the symbol is called a "pipe".

The command df | grep is "piping" (redirecting) the standard output of the df command into the standard input of the grep command. In this example the grep command filters the output of the df command. Then the awk commands is for display/format purposes.

Inside the regular expression it is specific to the grep syntax since it is surrounded by quotes it is only considered as an argument passed to grep

answered Jul 03 '18 at 08:42

xdrm

399
2
10

thanks bro it was useful – mo.khashab Jul 03 '18 at 08:57
@mo.khashab Happy to help. For further reading, jonrsharpe gave useful links in the comment section. – xdrm Jul 03 '18 at 09:00

what is "|" in Ubuntu or Linux in general

1 Answers1