less with multiple files; command to output filenames

Question

I want to be able to manually go through many files using less *.txt and then proceeding through the files using :n. If I determine that a file needs to be processed, then I want to be able to give a command that will, for example, send the current file name to stderr, so that once I am done going through all the files, I have a list of filenames to be processed. Is something like this possible? Is there another tool that is better for this purpose?

Answer 1

You can setup your own less special command key. Create file ~/.lesskey and place in it, at the start, the 2 lines:

#command
ok shell echo % >>/tmp/list\n

Then give the command

lesskey

to compile the file. Run your less command on your files and when you want to save the filename type the 2 chars ok. You will see echoed:

!echo myfilename >>/tmp/list
!done  (press RETURN)

which saves the current filename (%) into /tmp/list. Press return to continue. I chose the command ok arbitrarily. You can use any single character or character sequence you like. You can append the :n command to the end of the shell line in ~/.lesskey to also move on to the next file.

---

If you don't have lesskey I ran it on the above file and passed it through base64 as it contains some binary. Perhaps you can try using this:

echo 'AE0rR2MaAG9rAJtlY2hvICUgPj4vdG1wL2xpc3QKOm4AZQAAdgAAeEVuZA==' | base64 -d >~/.less

Answer 2

One way is to write a script that will do things with the least keystrokes, but if you have no time to write and thoroughly test a script, depending on what version of less you have, yes it is possible to use less.

Tested with less version 444, here is a sample walkthrough.

First, suppose you have four files a.txt b.txt c.txt d.txt

$ less *.txt

a.txt looks fine, so you view next using :n

b.txt looks bad, so to mark it you type:

! echo % | tee -a bad.txt

Less will respond:

b.txt
!done  (press RETURN)

You continue :n.

c.txt looks ok. You continue with :n

d.txt looks bad too, but you don't have to retype every single keystroke again, just ! and up-arrow, it will auto fill last command, and save d.txt to bad.txt

Then you q to quit less.

Now you can review the saved list:

$ cat bad.txt
b.txt
d.txt

Explanation

• The ! shell command runs of course a shell command, where % is the current file
• using tee is optional, just to have an additional indicator after you run the command, of what filename you just saved.
• -a appends, otherwise would overwrite and your bad.txt just has a single record
• you could have also just ! echo % >> bad.txt to append to bad.txt

Answer 3

When I need to do something like this, I'll use a tabbed terminal with less in one tab and vi in an adjacent tab.

When I get to a file I want to tag, I'll double-click on the filename at the bottom of the less screen, switch to the vi tab, middle-click paste it and hit ENTER, then switch back to the less tab.

If there's more than a couple of dozen files (i.e. it's likely to take me more than a few minutes), I'll try to figure out some way of automating the selection process with one or more of the usual tools: grep, awk, perl, etc.

grep for simple searches, awk or perl for more complicated ones.