find command to locate the
manual page
for the curl command on a
MacBook Pro running OS X as shown below:
$ find /usr/share/man -name curl\* /usr/share/man/man1/curl-config.1 /usr/share/man/man1/curl.1 $
There were two man pages with "curl" as part of the file name, but I only
wanted the second one, so I piped the output of find into
tail, selecting the last line of output only with the
-n 1 option.
$ find /usr/share/man -name curl\* | tail -n 1 /usr/share/man/man1/curl.1 $
I then wanted to have cat process that file name.
I could have just typed the directory path and file name produced from the
above sequence of commands or copied and pasted the result, of course, but I
thought it would be useful to know a method to get
cat to process the output from find
for other situations. There is a simple method, using
command substitution of getting cat to process a
file name that find has located. One can simply use a
command similar to cat `find [whatever]` as explained by Laurence
Gonsalves in response to a Stack Overflow question
How to pipe list of files returned by find command to cat
to view all the files. The command subsitution takes
the output of the command or commands between successive backtick characters and uses that as the argument
for another command, in this case the cat command.
So, in this case, I could use the command cat `find /usr/share/man
-name curl\* | tail -n 1`, which pipes the output of find
through tail with the output of that command serving as the
input filename to the cat command. Since, I wanted to then feed
the output of cat into the
groff command to convert
the curl man page to HTML, as explained at
Converting a man
page to HTML, PDF, text, I could then construct the final command below
to get the HTML version of the man page.
$ cat `find /usr/share/man -name curl\* | tail -n 1` | groff -mandoc -Thtml >curl.html stdin:275: warning [p 1, 49.2i]: cannot adjust line stdin:275: warning [p 1, 49.3i]: can't break line $
Alternatively, I can use another variant of the
command substitution technique within the Bash shell to achieve the same
effect by enclosing the command(s) I want to use to produce output that will
serve as the input to another command, in this case the cat
command, within the parentheses of $() as
noted by Stphane in
response to the same question and as shown below:
$ cat $(find /usr/share/man -name curl\* | tail -n 1) | groff -mandoc -Thtml >curl.html stdin:275: warning [p 1, 49.2i]: cannot adjust line stdin:275: warning [p 1, 49.3i]: can't break line $
Note: the commands above, though run from a Bash shell prompt obtained via the Terminal application on an Apple OS X system, will also work from a shell prompt on a Linux or Unix system as well.