How can I delete everything after the first column in Notepad++?

Solution 1:

If the data in the first column never contains a space, you can use a regular expression find and replace to get what you want.

In regular expression mode, search for:

^([^ ]*).*

And replace with

\1

What this does:

^ indicates that any match should start at the beginning of a line.
([^ ]*) is any expression that does not contain a space. The match is greedy, so this will match everything up to the first space (or the end of the line, whichever comes first).
.* is everything else on the line.

\1 refers to the part of the match inside the parentheses. That is, the entire line is replaced by just the bit from the first column.

Solution 2:

Here's a simpler regular expression you can use to achieve the same effect. Replace

 .*

(note the leading space)

with nothing. This will delete everything after and including the first space. This will work as long as your IP addresses are never prefixed with any whitespace (as is the case in your example).

Solution 3:

If you are using Windows and if you don't mind trailing spaces (you can find/replace them afterwards), use the Block Select feature:

1. Press and Hold the Alt key
2. Using the mouse, select the portion to delete (the entire block of text)
3. Release the Alt key
4. Delete that block of text
5. Repeat as necessary

Solution 4:

A regular expression is quicker, but you can do some really tricky things with macros if it is a more complicated task.

You could record a macro:

1. Cursor on line 1
2. Hit Start recording
3. Press key home
4. Hold Ctrl while you press key Right arrow (seven times)
5. Hold Shift while you press key End
6. Press key Delete
7. Press key Down arrow
8. Hit Stop recording

Then play it back:

9. Hit "Run a macro multiple times"
10. Type in the lines of the document minus 1, since the first line is complete.