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

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Archive for March 9th, 2020

MacOS: converting a man page to markdown

Posted by jpluimers on 2020/03/09

Converting a man page to markdown is a three step process:

  1. installing a tool that can convert the source of a man page to markdown
  2. finding the location of the man page source
  3. doing the actual conversion

Tool to convert man to markdown

The source format of man pages is troff, which is usually converted by man using groff, or a set of macros.

My initial thought for the first problem was to use pandoc, but as I found earlier in pandoc oneliner from reStructuredText to html, on MacOS, the pandoc can write groff format, but not read it.

Luckily doing a pandoc from groff to markdown – Google Search, I bumped into [WayBack] Convert groff to markdown · Issue #8 · neomutt/neomutt-docs · GitHub which lead to mandoc – Wikipedia.

Since I already had homebrew installed, getting mandoc was simple: brew install mandoc.

Finding the man page source

Earlier in the process when searching for pandoc based conversions, I found the solution for the second problem too: [WayBack] Man page with preserved text decorations, proportional text and fixed-width code – Unix & Linux Stack Exchange taught me about the -w option, but there is actually a -W option that works better if you have multiple pages for a keyword:

-w or --path
Don’t actually display the man pages, but do print the location(s) of the files that would be formatted or displayed. If no argument is given: display (on stdout) the list of directories that is searched by man for man pages. If manpath is a link to man, then “manpath” is equivalent to “man --path“.

-W Like -w, but print file names one per line, without additional information. This is useful in shell commands like man -aW man | xargs ls -l

Actual conversion for fsck_hfs

It all came down to a one-liner:

mandoc -T markdown `man -w fsck_hfs` > /tmp/

Note the order here is important this will fail with an error:

mandoc `man -w fsck_hfs` -T markdown > /tmp/

mandoc: -T: ERROR: No such file or directory
mandoc: markdown: ERROR: No such file or directory


Read the rest of this entry »

Posted in Apple, Mac, Mac OS X / OS X / MacOS, Power User | 1 Comment »

command line – Recursive tar compression? – Ask Ubuntu

Posted by jpluimers on 2020/03/09

Since I always forget one-letter command-line options: [WayBack]command line – Recursive tar compression? – Ask Ubuntu (thanks andrew.46 for this very nice answer!):


tar -czvf directorios.tar.gz folder

A few notes:

  1. Recursion is the default, from the tar man pages:
    -c, --create
        Create a new archive.  Arguments supply the names of the files to be archived.
        Directories  are  archived  recursively,  unless  the --no-recursion option is

    Although this can be turned off by using the --no-recursion option…

  2. You need the archive name immediately after the -f option, the correct sequence being:
    tar -c [-f ARCHIVE] [OPTIONS] [FILE...]
  3. For a more flexible command line (particularly if you wanted to use other compression utilities apart from gzip with tar) you could omit the -z option and use -a option to allow tar to automatically decide which compressor to use based on the archive suffix:
    -a, --auto-compress
        Use archive suffix to determine the compression program.

    Recognised suffixes are:

    • .gz : gzip
    • .tgz : gzip
    • .taz : gzip
    • .Z : compress
    • .taZ : compress
    • .bz2 : bzip2
    • .tz2 : bzip2
    • .tbz2 : bzip2
    • .tbz : bzip2
    • .lz : lzip
    • .lzma : lzma
    • .tlz : lzma
    • .lzo : lzop
    • .xz : xz

tar is pretty cool :)


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

GitHub – facebook/osquery: SQL powered operating system instrumentation, monitoring, and analytics.

Posted by jpluimers on 2020/03/09

Boy, I wish I had found this years ago: [WayBack] GitHub – facebook/osquery: SQL powered operating system instrumentation, monitoring, and analytics.

No more remembering all those nifty configuration and log file details by heart, just install and query using SQL.

Now you need to learn a “database” schema, however that’s the same for all supported operating systems.

Example installation steps:

Run interactively through osqueryi, then perform .help or .schema to get an impression of what is possible.

There is lots of documentation at [WayBack] osquery.


Posted in *nix, *nix-tools, Apple, Mac, Mac OS X / OS X / MacOS, Power User | Leave a Comment »

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