Linux redirection and pipelines, Linux redirection Pipelines

Linux redirection and pipelines, Linux redirection Pipelines
Standard output redirection

">" OPERATOR: overwrite the content of the target file

huey@huey-K42JE:~/huey/linux/cmdline$ date > foohuey@huey-K42JE:~/huey/linux/cmdline$ cat fooFri May 8 09:55:42 CST 2015

">" OPERATOR: append the output content to the end of the target file

huey@huey-K42JE:~/huey/linux/cmdline$ date >> foohuey@huey-K42JE:~/huey/linux/cmdline$ cat fooFri May 8 09:55:42 CST 2015Fri May 8 09:57:02 CST 2015

 

Standard Error redirection

"2>" OPERATOR: overwrite the content of the target file

huey@huey-K42JE:~/huey/linux/cmdline$ ls inexistent_dir 2> ls-error.txt huey@huey-K42JE:~/huey/linux/cmdline$ cat ls-error.txt ls: cannot access inexistent_dir: No such file or directory

"2>" OPERATOR: append the output content to the end of the target file

huey@huey-K42JE:~/huey/linux/cmdline$ ls inexistent_dir 2>> ls-error.txt huey@huey-K42JE:~/huey/linux/cmdline$ cat ls-error.txt ls: cannot access inexistent_dir: No such file or directoryls: cannot access inexistent_dir: No such file or directory

 

Redirects standard output and standard errors to the same file

"&>" OPERATOR: overwrite the content of the target file

huey@huey-K42JE:~/huey/linux/cmdline$ date &> foohuey@huey-K42JE:~/huey/linux/cmdline$ cat fooFri May 8 10:16:12 CST 2015huey@huey-K42JE:~/huey/linux/cmdline$ ls inexistent_dir &> foo huey@huey-K42JE:~/huey/linux/cmdline$ cat fools: cannot access inexistent_dir: No such file or directory

"&>" OPERATOR: append the output content to the end of the target file

huey@huey-K42JE:~/huey/linux/cmdline$ echo 'hello world' > foohuey@huey-K42JE:~/huey/linux/cmdline$ date &>> foohuey@huey-K42JE:~/huey/linux/cmdline$ ls inexistent_dir &>> foo huey@huey-K42JE:~/huey/linux/cmdline$ cat foohello worldFri May 8 10:25:24 CST 2015ls: cannot access inexistent_dir: No such file or directory

 

Standard input redirection

"<" Operator

huey@huey-K42JE:~/huey/linux/cmdline$ echo 'hello world' > foohuey@huey-K42JE:~/huey/linux/cmdline$ cat < foohello world

 

MPs queue

"|" Operator

huey@huey-K42JE:~/huey/linux/cmdline$ ls /usr/bin | grep '^zip'zipzipcloakzipgrepzipinfozipnotezipsplit