mjhjmtu

You could redirect the manpage to awk and extact the part:

man wget | awk '/^ *-b *.*$/,/^$/print'
 -b
 --background
 Go to background immediately after startup. If no output file is specified via the -o, output is redirected to wget-log.

That part is everything that is between a -b and an empty line.

If you use less as pager for man you can try

LESS="+/^s+-b" man wget

where

1. 
   + symbol to execute next operation after less has opened


2. 
   / command to start search


3. 
   ^s+-b regexp to match -b from start of line

So if you like you can arrange the apropriate function for shell

function rman 
#USAGE: rman programm.name option.to.search (with "-" symbol)
LESS="+/^s+$2" man "$1"

and add it into ~/.bashrc for example.

When you run man command you can press / and then enter the plain text to search for. For example, type /-b and it'll jump to the first instance of -b in the text.

I wrote a small script to do this called he, e.g. he wget -b.

The basic strategy is: search for the option (e.g. -b) as the first word on a line, then print until the next header, or next line with matching indentation.

If you can't use that, you can get something similar using basic sed, e.g.

man wget | sed -ne '/^ *-b/,/^$/p'

I use the following script that connects to explainshell.com. I copied it from reddit some time ago:

#!/bin/bash
cmd=$1
shift
args=$*
args=$args/ /+
w3m -dump "http://explainshell.com/explain/$cmd?args=$args"

I named it rman and put it in my $PATH. Usage for wget -b:

$ rman wget -b 
[logo]

 • about
 •
 • [ ]

wget(1) -b

The non-interactive network downloader

-b
--background
 Go to background immediately after startup. If no output file is specified via the -o, output is
 redirected to wget-log.

source manpages: wget

You can tweak this script a little to not to show garbage at the beginning.

EDIT: I got it from here. Thanks to the author!

Alternatively, if your grep is the GNU grep, you can use it as follows:

man wget | grep -EA3 '^ *-b'

In which -A (a GNU extension) is for print number of lines after matching lines (here 3). you can use appropriate number for complete description.

Example:

$ man wget | grep -EA3 '^ *-b'
 -b
 --background
 Go to background immediately after startup. If no output file is specified via the -o, output is
 redirected to wget-log.

$ man grep | grep -EA3 '^ *-A'
 -A NUM, --after-context=NUM
 Print NUM lines of trailing context after matching lines. Places a line containing a group separator
 (--) between contiguous groups of matches. With the -o or --only-matching option, this has no effect
 and a warning is given.