how to using Linux pipe command output another commandhow to using Linux pipe command output another command's help content to a file tee overwrite append > >>



how to using Linux pipe command output another command's help content to a file

Linux tee > >>

how to using Linux pipe command output another command

gcc help

$ gcc --help
# ❌ ???
$ gcc --help | echo > gcc-help.md

# output help to a file ✅
$ gcc --help > gcc-help.md


​>​​ && ​​>>​

# > overwrite file
$ gcc --help > gcc-help.md

# >> append data
$ gcc --help >> gcc-help.md


total 10 ways

         || visible in terminal ||   visible in file   || existing
Syntax || StdOut | StdErr || StdOut | StdErr || file
==========++==========+==========++==========+==========++===========
> || no | yes || yes | no || overwrite
>> || no | yes || yes | no || append
|| | || | ||
2> || yes | no || no | yes || overwrite
2>> || yes | no || no | yes || append
|| | || | ||
&> || no | no || yes | yes || overwrite
&>> || no | no || yes | yes || append
|| | || | ||
| tee || yes | yes || yes | no || overwrite
| tee -a || yes | yes || yes | no || append
|| | || | ||
n.e. (*) || yes | yes || no | yes || overwrite
n.e. (*) || yes | yes || no | yes || append
|| | || | ||
|& tee || yes | yes || yes | yes || overwrite
|& tee -a || yes | yes || yes | yes || append


tee

# output help to a file ✅
$ gcc --help | tee gcc-help.txt

# > overwrite file
$ gcc --help > gcc-help.txt
# >> append data
$ gcc --help >> gcc-help.txt