Extracting a 7-Zip file “silently” - command line option

Question

I want to extract a 7-Zip archive in a Python script. It works fine except that it spits out the extraction details (which is huge in my case).

Is there a way to avoid t

Answer 1

7-zip has not such an option. Plus the lines printed at each file compressed are supposed to display at the same spot without newline, erasing the previous one, which has a cool effect. Unfortunatly, in some contexts (Jenkins...) it produced several lines ☹️ flooding the console.

NUL (windows) is maybe one solution.

7-zip.exe -o some_dir x some_archive.7z>NUL

Answer 2

As told by Fr0sT above, -ba switch outputs only valid things (at least in list option on which I was trying). 7z.exe l archive_name.zip

7z.exe l -ba archive_name.zip

made great difference, esp for parsing the output in scripts. There is no need to modify anything, just use -ba switch in version19. This was also told bysomeone above. I'm putting as answer as I can't comment.

Answer 3

Like they said, to hide most of the screen-filling messages you could use ... some_archive.7z | FIND /V "Compressing" but that "FIND" would also remove the error messages that had that word. You would not be warned. That "FIND" also may have to be changed because of a newer 7-zip version.

7-zip has a forced verbose output, no silence mode, mixes stderr and stdout(*), doesn't save Unix permissions, etc. Those anti-standards behaviors together put "7-zip" in a bad place when being compared to "tar+bzip2" or "zip", for example.

(*) "Upstream (Igor Pavlov) does not want to make different outputs for messages, even though he's been asked several times to do so :(" http://us.generation-nt.com/answer/bug-346463-p7zip-stdout-stderr-help-166693561.html - "Igor Pavlov does not want to change this behaviour" http://sourceforge.net/tracker/?func=detail&aid=1075294&group_id=111810&atid=660493

Answer 4

If you're running 7-zip.exe from Powershell, and you only want to see errors, then you could try something like this:

7-zip.exe u <Target> <Source> | Select-String "Error" -Context 10

This will only display the "Error" message line and the surrounding 10 lines (or whatever number) to capture the error specific output.

Answer 5

I just came across this when searching for the same, but I solved it myself! Assuming the command is processed with Windows / DOS, a simpler solution is to change your command to:

7z.exe -o some_dir x some_archive.7z > nul

That is, direct the output to a null file rather than the screen.

Or you could pipe the output to the DOS "find" command to only output specific data, that is,

7z.exe -o some_dir x some_archive.7z | FIND "ing archive"

This would just result in the following output.

Creating archive some_archive.7z

or

Updating archive some_archive.7z**

---

My final solution was to change the command to

... some_archive.7z | FIND /V "ing  "

Note double space after 'ing'. This resulted in the following output.

7-Zip 9.20  Copyright (c) 1999-2010 Igor Pavlov  2010-11-18

Scanning

Updating some_archive.7z


Everything is Ok

This removes the individual file processing, but produces a summary of the overall operation, regardless of the operation type.

Answer 6

Expanding on @Matthew 's answer and this answer https://superuser.com/questions/194659/how-to-disable-the-output-of-7-zip I'm using FINDSTR instead of find so I can chain multiple lines to exclude and blank lines as well:

7za.exe a test1.zip .\foldertozip | FINDSTR /V /R /C:"^Compressing  " /C:"Igor Pavlov" /C:"^Scanning$" /C:"^$" /C:"^Everything is Ok$"

• /V: exclude
• /R: regex
• /C:"^Compressing " : begining of line, Compressing, 2 spaces
• /C:"^Scanning$" : the word Scanning on its own on a line (begining/end)
• /C:"^$" : a begining and end without anything in between, ie, a blank line

I'm using /C so that a space is a space, otherwise it's a separator between multiple words to exlude as in this simpler version:

FINDSTR /V "Compressing Pavlov Scanning Everytyhing"

(the same caveats exist, if the wording changes in a new version, or if a useful line starts with the word "Compressing ", it will not work as expected).