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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘*nix’ Category

How to Configure and Manage Network Connections Using ‘nmcli’ Tool

Posted by jpluimers on 2017/09/22

Via “In the form over function era: Using Network Manager from the command line” [WayBack]:

As a Linux administrator you’ve got various tools to use in order to configure network connections, such as: nmtui, NetworkManager GUI and nmcli in Linux

Source: How to Configure and Manage Network Connections Using ‘nmcli’ Tool [WayBack]

–jeroen

Posted in *nix, *nix-tools, Linux, Power User | Leave a Comment »

Don’t Use Regular Expressions To Parse IP Addresses!

Posted by jpluimers on 2017/09/21

Interesting piece: Don’t Use Regular Expressions To Parse IP Addresses! [WayBack]

TL;DR:

When have neither then for quad-dotted decimal IPv4 addresses (ignoring for instance octals and grouped quads), this is suitable: regex – Regular expression to match DNS hostname or IP Address? – Stack Overflow [WayBack]

ValidIpAddressRegex = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$";

Which explained looks like this:

https://regex101.com/r/Wyr2Zd/1

Regular expression:

/ ^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$ / g

Explanation:

  • ^ asserts position at start of the string
    • 1st Capturing Group (([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}
      • {3} Quantifier — Matches exactly 3 times
        A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you’re not interested in the data

        • 2nd Capturing Group ([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])
          • 1st Alternative [0-9]
            • Match a single character present in the list below [0-9]
              0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
          • 2nd Alternative [1-9][0-9]
            • Match a single character present in the list below [1-9]
              1-9 a single character in the range between 1 (ASCII 49) and 9 (ASCII 57) (case sensitive)
            • Match a single character present in the list below [0-9]
              0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
          • 3rd Alternative 1[0-9]{2}
            • 1 matches the character 1 literally (case sensitive)
            • Match a single character present in the list below [0-9]{2}
              {2} Quantifier — Matches exactly 2 times
              0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
          • 4th Alternative 2[0-4][0-9]
            • 2 matches the character 2 literally (case sensitive)
            • Match a single character present in the list below [0-4]
              0-4 a single character in the range between 0 (ASCII 48) and 4 (ASCII 52) (case sensitive)
            • Match a single character present in the list below [0-9]
              0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
          • 5th Alternative 25[0-5]
            • 25 matches the characters 25 literally (case sensitive)
            • Match a single character present in the list below [0-5]
              0-5 a single character in the range between 0 (ASCII 48) and 5 (ASCII 53) (case sensitive)
        • \. matches the character . literally (case sensitive)
    • 3rd Capturing Group ([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])
      • 1st Alternative [0-9]
        • Match a single character present in the list below [0-9]
          0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
      • 2nd Alternative [1-9][0-9]
        • Match a single character present in the list below [1-9]
          1-9 a single character in the range between 1 (ASCII 49) and 9 (ASCII 57) (case sensitive)
        • Match a single character present in the list below [0-9]
          0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
      • 3rd Alternative 1[0-9]{2}
        • 1 matches the character 1 literally (case sensitive)
        • Match a single character present in the list below [0-9]{2}
          {2} Quantifier — Matches exactly 2 times
          0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
      • 4th Alternative 2[0-4][0-9]
        • 2 matches the character 2 literally (case sensitive)
        • Match a single character present in the list below [0-4]
          0-4 a single character in the range between 0 (ASCII 48) and 4 (ASCII 52) (case sensitive)
        • Match a single character present in the list below [0-9]
          0-9 a single character in the range between 0 (ASCII 48) and 9 (ASCII 57) (case sensitive)
      • 5th Alternative 25[0-5]
        • 25 matches the characters 25 literally (case sensitive)
        • Match a single character present in the list below [0-5]
          0-5 a single character in the range between 0 (ASCII 48) and 5 (ASCII 53) (case sensitive)
  • $ asserts position at the end of the string, or before the line terminator right at the end of the string (if any)
  • Global pattern flags
    g modifier: global. All matches (don’t return after first match)

–jeroen

Posted in *nix, Communications Development, Development, Internet protocol suite, Network-and-equipment, Power User, Software Development, TCP | Leave a Comment »

Re: [opensuse-factory] dup –no-allow-vendor-change is now default

Posted by jpluimers on 2017/09/15

I totally missed this announcement 2 months ago:

after this update, zypper dup will default to –no-allow-vendor-change, whichhas been the recommended way for Tumbleweed for a long time now.

Source: Re: [opensuse-factory] dup –no-allow-vendor-change is now default

So Dominique was glad to “rub the salt” a bit (:

[WayBack/Archive.isDominique / DimStar‏ @DimStar Replying to @sysrich @jpluimers: for the record: –no-allow-vendor-change has become the default in Tumbleweed, see also http://dominique.leuenberger.net/blog/2017/06/review-of-the-week-201726/

It was documented at least on these places:

–jeroen

Read the rest of this entry »

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »

youtube-dl – saving both audio and video without keeping intermediate files seems impossible

Posted by jpluimers on 2017/09/14

Just in case someone has a better alternative than youtube-dl alias:

alias youtube-dl-audio-and-video='youtube-dl --keep-video --extract-audio --audio-quality 0 --audio-format mp3'

It extracts the audio and keeps the video.

The result is that also all intermediate downloads are being kept.

So even after studying the README extensively the only alternative seems to be a double download like this:

youtube-dl-audio-and-video() { youtube-dl --extract-audio --audio-quality 0 --audio-format mp3 $1; youtube-dl $1; }

–jeroen

Posted in *nix, *nix-tools, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »

zypper errors on download.opensuse.org

Posted by jpluimers on 2017/09/13

If you see error message like below when performing zypper refresh or zypper dist-upgrade, then please inform the opensuse team (for instance Twitter or the #openSUSE-factory IRC channel) as this is part of the aftermath of the download.opensuse.org trouble that started last week.

Permission to access 'http://download.opensuse.org/ports/aarch64/tumbleweed/repo/oss/suse/setup/descr/appdata-icons.tar.gz' denied.

What happened to me with Raspberry Pi 3 and Tumbleweed is below and fixed because after I got in touch: the data restore had worked out OK, but the permissions didn’t.

I got there as the search for “Permission to access ‘http://download.opensuse.org/ports/aarch64/” got me to [WayBack] TUMBLEWEED Zypper Permission to access:

Unfortunately there was a catastrophic issue last week with the openSUSE download system (read: stuff is still broken and not all mirrors are fully functional).

–jeroen

Read the rest of this entry »

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »

 
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