What is a way to read man pages in Vim without using temporary files

Question

I want to be able to read man pages in Vim.

For some reason, it seems that Vim isn't able to read the output of programs through piping. E.g (man ls) | vi doesn't seem to work, bonus points for somebody who can explain why.

To get around this, I've been using the following little script:

tempo = `mktemp`
man $1 > $tempo ; vi $tempo

This script uses temporary files which I guess work fine, but I was wondering if there was a good way to read man pages in Vim without resorting to creating temporary files

Solution 1

For some reason, it seems that vim isn't able to read the output of programs through piping […]

According to the man-page, you need to specify a file of - to get it to read from standard input; so:

man ls | vi -

If that doesn't work, you might try using process substitution:

vi <(man $1)

which creates a sort of pseudo-file and passes it to vi.

Solution 2

Vim includes a man page viewer, :Man, in its runtime files.

Put this line in your vimrc:

runtime! ftplugin/man.vim

Now you can read syntax-highlighted man pages inside Vim by running :Man. For example:

:Man 3 printf

Even better, you can just place your cursor on a word in the buffer and press <Leader>K (\K) to see the man page for that word.

See :h find-manpage for complete usage and installation instructions.

Solution 3

On my system (Mac OS X), I found that the above left control characters in the output. Instead I used:

export MANPAGER="col -b | vim -MR - "

then just e.g.

man vim

The vim options turn off modifying the buffer and make it read-only. This stops vim complaining if you try to exit with ":q" (you can use :q! of course, but you might as well set the options).

This is also handy for general use - I have the following. The -c command names the buffer, just for completeness.

alias vimpager="vim -MR -c 'file [stdin]' -"

Solution 4

Here is what I did: I've made a function in my .bashrc:

vman() { vim <(man $1); }

When I call vman this automatically calls Vim showing the man page. It works great.

Solution 5

By default vim reads vimscripts (=vim commands), not input files, from stdin. That is why you cannot directly pipe man output to vim; as others have mentioned you have to use vim - to make vim read from stdin.

However piping vimscripts can be useful too:

vim test.txt <<EOF
:%s/[aiueo]/X/g
:wq! output.txt
EOF

The above will use vim to open test.txt, replace all vowels with X, write the results to output.txt, and quit (ignoring changes to the original file). It uses a here document but you can of course put the vim commands in a file and use vim test.txt < myscript or cat myscript | vim test.txt to achieve the same result.

I suspect the reason they did it this way was that you can open multiple input files but only execute one script. If input was read from stdin by default, you could only read one buffer that way.

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