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View Unix man (help) pages in Preview

Today’s tip goes well with yesterday’s tip, which explained how to open any Finder item’s folder in Terminal via Keyboard Maestro. Once in Terminal (and sometimes even when not in Terminal), I’ll often want to check out the man page (help) for a given command.

You can do this directly in Terminal with man [name of command], of course, but then it opens on top of whatever you were working on, and you have to read it in Terminal. You could use another tab or window, but you’d still be reading in Terminal. There are times, too, when I’m writing about the Unix side of macOS, so I’m not even in Terminal, but still want to view a man page.

My solution to this problem is two different ways of doing the same thing: I open man pages as nicely-formatted PDFs in Preview. The method I use to get to that point depends on if I’m working in Terminal or not.

Update: I’ve modified the script and macro so that they properly handles two-argument man commands, such as man 3 printf.

In Terminal

Based on an old Mac OS X Hints tip, I created a very simple shell script:

The key to this little script is the -t option on the man command. From the (hehe) man man help file, here’s what that does:

  -t     Use /usr/bin/groff -Tps -mandoc -c to format the manual page,
         passing the  output to stdout. The default  output format  of
         /usr/bin/groff -Tps -mandoc -c is  Postscript, refer  to  the
         manual  page  of /usr/bin/groff -Tps -mandoc -c for  ways  to 
         pick an alternate format.

In other words, the -t converts the help page into a PostScript file, which is something that Preview can easily open (which is just what the last line of the script does).

I named this script preman, because it uses Preview to open man pages. Once saved, I made it executable (chmod 755 preman), and I can then open any man page in Preview by typing, for instance, preman bash.

The output is nicely formatted, and by opening the man page in Preview, my Terminal session is uninterrupted. A quick adjustment with Moom, where I have a saved layout to position Preview and Terminal, and I can scan the man page while working in Terminal.

But what about when I’m not in Terminal? For that, I basically implement the same shell script, but with it set up to run within a Keyboard Maestro macro.

Not in Terminal

Instead of switching to Terminal to view a man page when I’m not already in Terminal, I activate a global Keyboard Maestro macro that asks me which man page I want to view, then runs the above bash script.

When I activate the macro (using Control-Option-U), here’s what I see:

I can change the default from bash, of course, but as I have yet to memorize all 64 pages of the bash help file, I find myself looking at it somewhat often. If I want the bash man page, I just hit return; otherwise, I type the name of the command then hit Return.

The macro itself is quite simple; here’s how it looks. (You can, of course, download the macro for your own use.)

The one thing this macro demonstrates is how to use a Keyboard Maestro variable in a shell script: You use the $KMVAR_variable-name construct. This is different than when referencing a variable in non-shell-script uses, where the format is %Variable%variable-name%.

The shell script that I’m executing in Keyboard Maestro is exactly the same as the saved script, except it’s written all on one line.

The last entry in the macro just deletes the variable, so that I don’t clutter Keyboard Maestro’s variable list (because all variables are global and permanent).

It’s a simple little macro, but it’s a big timesaver when I need it, and I find it so much easier to read man pages in Preview than in Terminal.

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