/dev/null commands in Linux

/dev/null : Represents an empty device file

> : Where does the delegate redirect to, for example: echo "123" >/home/123.txt
1 : Indicates stdout standard output, system default is 1, so ">/dev/null" is equivalent to "1>/dev/null"
2 : indicates stderr standard error
& : Means equal to, 2>&1, 2 output redirect equals 1

1. Prohibit standard output

>/dev/NULL

2. Prohibit standard error

[[email protected] log]# RM filename1 RM: Cannot delete " filename1 "  2>/dev/null

3. Prohibit standard output and standard error

[[email protected] log]# RM filename1rm: Cannot delete " filename1 "  >/dev/null2>&1

4, clear the contents of the file

/dev/null >   filename [[email protected] log]# cat filename

/dev/null commands in Linux