UNIX for Dummies Questions & Answers

Hey I am learning shell-script as a beginner. I wanted to know how I can print out the number of lines in a command, is that possible first? I know of the command wc but it only works with file? What I want to do is, say I type in man ps and I get sooooo many lines. So I wanted to know if it is possible that I ask the programme to tell me the number of lines in that command or even go further and look for lines that contain the letters pr, for example.

You can use

Code:

ps -ef | grep pr

or to just know the count of lines that match the string "pr" you can use:

Code:

ps -ef | grep -c pr

Thank you Pad. Just to understand more. What if I want to add an option to the command? Say instead of ps, I want to type ps -e.

Oh OK. I just tested it, seems you just add the option. Thank you!

Hey sorry, it is not working. I mean if I want to know number of lines in a command, I use? I tried to use ps -ef | grep without the pr because I wanted to know only the number of lines in the command ps but it does not work. My question is, how can I know the number of lines in a command and also specifically number of certain pair of letters say PS only in a certain command?

the "-c" option with grep will provide a count of the lines that match the search criteria.

Maybe I don't understand your question. I was assuming that "number of lines in a command" meant "number of lines of output resulting from an executed command".

OK, I will explain. There are numerous commands as you know and with the man page you can know about this command. So let us say, I type in man ls for example, or with an option man ls -l, and I get info about this command. Now what I want to do is this: I want to ask the program to tell me how many lines will the man page display about this specific command, in our example ls or with option ls -l. And then again ask about how many specific pair of letters come up in the man pages of this command. So using our example again (ls), I want to ask the programme how many of the letters lm appear in each line of the man pages of this command, for example. To sum up.

I want to know:
1. How many lines about a certain command appear in the man pages when I type man command or man comman -option.
2. How many pair of words appear in each line. So for example to know how many lm appear in each lien of this command in the man pages.

Hope it is a bit clear now. Sorry, if I didn't make it clear before!