Linux Command Line - I/O Redirection
2017-06-13
Streams
0
,stdin
is standard input.1
,stdout
is standard output.2
,stderr
is standard error.
Standard Input
Transmitted through the keyboard, from the user to a program. It is terminated when the end of file (EOF) is reached.
Standard Output
Display data generated by a program on the terminal if it is not redirected.
Standard Error
Display errors generated by a program on the terminal if it is not redirected.
Overwrite Target
>
,1>
standard output.<
standard input.2>
standard error.&>
standard output and standard error.i>&j
redirect anything that targetsi
toj
.2>&1
standard error to standard output
Append Target
>>
,1>>
standard output.<<
standard input.2>>
standard error.
Pipes
Redirect streams from one program to another.
Filters
Alter piped redirection and output: find, grep, tee, tr, wc.
/dev/null
special file that trashes any data that it receives. You can redirect output that you do not want displayed or passed to another program.