[Posts] the Linux Guide (12) - linux input and output redirection

Linux Tutorials (12) - linux input and output redirection

2018-08-21 22:57:02  money Tingting  read the number 49 more

Category Column:  Linux tutorials and operation of  Linux tutorials and use

 

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Input and output redirection 
command> file // standard output redirected to a file - covering 
command >> file // standard output redirected to a file - Append 
 
command 2> // standard error redirected to file - covering 
Command 2 >> // standard error is redirected to a file - append 
 
command 2> / dev / null // redirect standard error to the Recycle Bin 
 
command &> file // standard output and standard error redirected to file - covering 
 
command >> file 2> & 1 // standard output and standard error redirected to file - append 
 
 
 
such as 
[root @ localhost tmp] # DATE> abc 
[root @ localhost tmp] # DATE >> abc 
[root @ localhost tmp] # CAT / etc / passwd> abc

[root@localhost tmp]# 1234 2> abc 
[root@localhost tmp]# 1234 2> /dev/null

[root@localhost tmp]# 1234 >> abc 2>&1

With scheduled tasks 
/ 1  * * * DATE >> / tmp / abc 
 
character: |. This is the pipe character. 
Two acts: 
1, nexus: the input on the output as an instruction to execute an instruction. 
2, with grep character to achieve filtering.

[root@localhost tmp]# ls -l /etc/ | more 
[root@localhost tmp]# ps -aux | grep cron 
[root@localhost tmp]# ps -aux | grep cron > abc