Unix lines in a file

But expr is lousy for getting, say, the fourth word Reading a file after nth line. I know how to read a file line by line. But don't to how to skip to a line matching a criteria and then continue reading it till the end.

This is a log file. The input is a timestamp. Find the timestamp in the log file 2. Read the remaining lines one at a time till EOF. How can I do Hi, I have a file split. How to get nth line from a file usuing commands. Hi to all, I have a file with lines,Now i need to get th record.

So please any one help me out from this. Thanks in advance. Sathish 3 Replies. RedHat Commands. I have already run sort on both the files. I spent lot of time to find the answer for this question, so documenting it for future reference. By default, comm outputs 3 columns: left-only , right-only , both. The -1 , -2 and -3 switches suppress these columns. So, hides the right-only and both columns, showing the lines that appear only in the first left file.

If you want to find lines that appear in both, you can use , which hides the left-only and right-only columns, leaving you with just the both column. The simple answer did not work for me because I didn't realize comm matches line for line, so duplicate lines in one file will be printed as not-existing in the other.

For example, if file1 contained:. In my case, I wanted to know only that every string in file2 existed in file1, regardless of how many times that line occurred in each file.

Solution 2: the first "working" answer I found from unix. Note that if file2 contains duplicate lines that don't exist at all in file1, fgrep will output each of the duplicate lines. Also note that my totally non-scientific tests on a single laptop for a single fairly large dataset showed Solution 1 using comm to be almost 5 times faster than Solution 2 using fgrep.

I am not sure why it has been said diff should not be used. This is document acri in the Knowledge Base. Last modified on Skip to: content search login.

Knowledge Base Toggle local menu Menus About the team. Knowledge Base Search. Log in. These examples are just to let you know that there are multiple ways to count the lines without using "wc -l". But if asked I will always use "wc -l" instead of these options as it is way too easy to remember. Along with the above commands, its good to know some rarely used commands to find the line count in a file. Use the nl command line numbering filter to get each line numbered.

The syntax for the command is:.