in shell | usage

| operator

The pipe symbol is a very powerful feature of Unix. The symbol is a vertical bar: "|".
usage:

command 1 | command 2

Its function is to pass the result of the execution of the first command command 1 to command 2 as the input of command 2

example:

ideviceinstaller -u udid -l|awk '{print $1}'|grep com.test.XXXX

ideviceinstaller -u udid -l List installed third-party apps

awk '{print $1}' keep the third-party application results from the previous row in the first column

grep com.test.XXXX searches for com.test.XXXX in the first reserved column