itabs copies infile to outfile, replacing every sequence of spaces leading up to a tab position by a tab character.
outfile will look the same as infile, provided the tab size used by itabs is the same as that 'assumed' in infile.
The default tab size is 3, giving tab positions 4, 7, 10 ...
itabs writes a one-line report to standard error (or logfile, if used) when done, e.g.:
itabs: 15 tabs inserted
If you don't specify infile, itabs reads from standard input.
If you don't specify outfile, itabs writes to standard output.
If you don't specify logfile, itabs writes error messages to
standard error.
-nX : Use tab size X (2..128) instead of default 3.
-v : Print version banner and usage info to standard error (or logfile, if given), then exit.