Dmitry Gutov <dmitry@gutov.dev> writes:
On 01/02/2024 05:38, john muhl via Bug reports for GNU Emacs, the
Swiss army knife of text editors wrote:
The grep on Alpine does not support the --null option.
$ grep --null test *
grep: unrecognized option: null
BusyBox v1.36.1 (2024-01-16 17:10:30 UTC) multi-call binary.
To reproduce:
emacs -Q
M-: (project-find-regexp "test")
Debugger entered--Lisp error: (user-error "Search failed with status
123: grep: unrecognized option: null")
signal(user-error ("Search failed with status 123: grep: unrecognized option:
null"))
Hi!
That's a problem: apparently it does indeed not support --null or -Z:
https://boxmatrix.info/wiki/Property:grep
There is another flag we could use, which seems to have a similar
enough effect: -z. But from what I can tell, it would make OpenBSD
unsupported: https://man.openbsd.org/grep
Even -z is a compile time option:
$ busybox grep -h
BusyBox v1.36.1 (2024-01-16 17:10:30 UTC) multi-call binary.
Usage: grep [-HhnlLoqvsrRiwFE] [-m N] [-A|B|C N] …
https://git.busybox.net/busybox/tree/findutils/grep.c#n85
I couldn’t get busybox to compile with the EXTRA_COMPAT option
so can’t say if it helps or not.
Perhaps it would be best to just file a feature request for busybox's
support for --null/-Z. Better ideas welcome.
In the meantime, you can customize the entry for 'grep' in
xref-search-program-alist to use -z.
Would it be possible to have xref check
grep-use-null-filename-separator and only use --null when
available? I tried with this crude patch and the results look
good enough:
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -1855,7 +1855,11 @@ xref-search-program-alist
`((grep
.
;; '-s' because 'git ls-files' can output broken symlinks.
- ,(concat "xargs -0 " xargs-max-chars "grep <C> --null -snHE -e <R>"))
+ ,(concat "xargs -0 " xargs-max-chars "grep <C>"
+ (when (and (grep-compute-defaults)
+ grep-use-null-filename-separator)
+ " --null")
+ " -snHE -e <R>"))
(ripgrep
.
;; '!*/' is there to filter out dirs (e.g. submodules).