[SOLVED] Vimscript: using substitute() on a variable

porphyry5 · 10-08-2011, 12:30 PM

If I paste the output of :ls into a buffer, the command

Code:

:%s/.*\(\".*\"\).*/\1/

reduces that output to just the file paths. Wanting to achieve that result in a variable, I did

Code:

:redir => x|silent :ls|redir END
:let y = substitute(x, ".*\(\".*\"\).*", "\1", "g")

which accomplished absolutely nothing, y is identical to x. I've tried umpteen variations on that substitute command, getting only the same result, or a bunch of error messages. How should I be specifying it?

I was following the examples used in :h substitute() which both use ". But if I do

Code:

:let y = substitute(x, '.*\(".*"\).*', '\1', "g")

I do get output, but only the match to the last line in the variable x. I tried concatenating the output by

Code:

:let y = y . substitute(x, '.*\(".*"\).*', '\1', "g")

but that just appended the same output again to variable y. But the question has changed. How do I get every line of output from that substitute() command?

rch · 10-08-2011, 08:50 PM

I assume you surely meant :!ls. What I don't get is the regex that you are using. So, you are matching anything .* followed by quotation followed by anything .* followed by quotation and then match anything (.*). You are substituting whatever you are getting between the quotation marks. Just out of curiosity, could you please give me what/ how are you reducing the output from !ls to file paths?

Quote:

Originally Posted by porphyry5

If I paste the output of :ls into a buffer, the command

Code:

:%s/.*\(\".*\"\).*/\1/

reduces that output to just the file paths. Wanting to achieve that result in a variable, I did

Code:

:redir => x|silent :ls|redir END
:let y = substitute(x, ".*\(\".*\"\).*", "\1", "g")

which accomplished absolutely nothing, y is identical to x. I've tried umpteen variations on that substitute command, getting only the same result, or a bunch of error messages. How should I be specifying it?

I was following the examples used in :h substitute() which both use ". But if I do

Code:

:let y = substitute(x, '.*\(".*"\).*', '\1', "g")

I do get output, but only the match to the last line in the variable x. I tried concatenating the output by

Code:

:let y = y . substitute(x, '.*\(".*"\).*', '\1', "g")

but that just appended the same output again to variable y. But the question has changed. How do I get every line of output from that substitute() command?

porphyry5 · 10-09-2011, 04:54 AM

Quote:

Originally Posted by rch

I assume you surely meant :!ls. What I don't get is the regex that you are using. So, you are matching anything .* followed by quotation followed by anything .* followed by quotation and then match anything (.*). You are substituting whatever you are getting between the quotation marks. Just out of curiosity, could you please give me what/ how are you reducing the output from !ls to file paths?

No, I did not mean :!ls; that accesses the linux ls, which, at least on my system, delivers only the terminating name. I meant vim's ls, which, among other things, returns "the path used to open that file in vim". As I only ever use a single instance of vim, always started the same way in the same working directory, the file paths returned by vim's ls are sufficient for my purpose. The regex, used in the :substitute command, delivers the enquoted file path; used in the substitute() function it returns only the last occurrence of such.

Following is my solution.
The variable x contains

Code:

1 #    "~/Session.vim"                line 5
2      "~/.vimrc"                     line 34
3      ".vim/vscripts/makesess.vim"   line 4
4      "~/Documents/vimcht"           line 62
5      "~/.fluxbox/startup"           line 5
6      "~/Documents/Notes"            line 2604
7      "~/Documents/bashcht"          line 21
8 %a   "junk"                         line 10

By my reading of :h /[], particularly "...Without the "\_" or "\n" the collection does not match an end-of- line...", then

Code:

:let y = ""
:let y = substitute(x, '[.]*\("[.]*"\)[.]*', '\1', "g")

should have done the job. But it delivered

Code:

"junk"

just as it did without the [].
I then tried

Code:

:let y = ""
:let y = substitute(x, '[^\n]*\("[^\n]*"\)[^\n]*', '\1', "g")

and got exactly the same result.

Clearly vim does not use the actual newline character internally, for variables as well as registers. So it treats a variable as a single line. Which led me to this solution

Code:

:let y = substitute(x, '[^"]*\("[^"]\+"\)[^"]*', ':tabe \1\n', 'g')

yielding

Code:

:tabe "~/Session.vim"
:tabe "~/.vimrc"
:tabe ".vim/vscripts/makesess.vim"
:tabe "~/Documents/vimcht"
:tabe "~/.fluxbox/startup"
:tabe "~/Documents/Notes"
:tabe "~/Documents/bashcht"
:tabe "junk"

Then I discovered that vim is not bash, and won't write a file from a variable, only from a list. So my final solution became

Code:

:redir => x|silent :ls|redir END
:let ylist = eval('[' . substitute(x, '[^"]*"\([^"]\+\)"[^"]*', '":tabe \1", ', 'g') . '""]')
:call writefile(ylist, "/home/g/Session.vim", "")

This yields a Session.vim that will open all the files that were open when Session.vim was created.