The is famous for printing a file neatly on a page - with margins at top and bottom, filename, date, and page numbers. It can also print text in columns: one file per column or many columns for each file.
The -t option takes away the heading and margins at the top and bottom of each page. That's useful when you want data "pasted" into columns with no interruptions.
The -m option reads all files on the command line simultaneously and prints each in its own column, like this:
pr -m -t
file1 file2 file3The lines The lines The lines of file1 of file2 of file3 are here are here are here ... ... ...
pr may use TAB characters between columns.
If that would be bad, you can pipe pr's output through
X option that
sets the column separator to the single character X.
An option that's a number will print a file in that number of columns. For instance, the -3 option prints a file in three columns. The file is read, line by line, until the first column is full (by default, that takes 56 lines). Next, the second column is filled. Then, the third column is filled. If there's more of the file, the first column of page 2 is filled - and the cycle repeats:
pr -3 file1Nov 1 19:44 1992 file1 Page 1 Line 1 here Line 57 here Line 115 here Line 2 here Line 58 here Line 116 here Line 3 here Line 59 here Line 117 here ... ... ...
The columns aren't balanced - if the file will fit into one column, the other columns aren't used. You can change that by adjusting -l, the page length option; see the section below.
Do you want to arrange your data across the columns, so that the first three lines print across the top of each column, the next three lines are the second in each column, and so on, like this?
pr -l1 -t -3 file1Line 1 here Line 2 here Line 3 here Line 4 here Line 5 here Line 6 here Line 7 here Line 8 here Line 9 here ... ... ...
Use the -l1 (page length 1 line) and -t (no title) options. Each "page" will be filled by three lines (or however many columns you set). You have to use -t; otherwise, pr will silently ignore any page lengths that don't leave room for the header and footer. That's just what you want if you want data in columns with no headings.
If you want headings too, pipe the output of pr through another pr:
pr -l1 -t -3 file1 | pr -h file1Nov 1 19:48 1992 file1 Page 1 Line 1 here Line 2 here Line 3 here Line 4 here Line 5 here Line 6 here Line 7 here Line 8 here Line 9 here ... ... ...
-h file1 puts the filename into the heading.
Also seeand . Of course, programming languages like and can also make text into columns.