I completely despise that the option is called "--null".
Someone was a complete idiot.
Ted Unangst <t...@tedunangst.com> wrote:
> On 2021-01-22, Omar Polo wrote:
> >
> > quasi three-weekly ping.
> >
> > Is this such a bad idea?
>
> This seems reasonable. I think there's no need to change print line calls
> though, just patch the implementation once.
>
> >
> > (TBH: I have still to look at how to write a regression test for this)
> >
> > Omar Polo <o...@omarpolo.com> writes:
> >
> > > Hello,
> > >
> > > There are various program, especially the one written with GNU grep in
> > > mind, that expects various flags that grep in base doesn't have. While
> > > some of the flags (like --color) can be easily worked out (i.e. by
> > > patching/customising these programs) one thing that it isn't easily
> > > workable is --null, because it alters the way grep outputs its data.
> > >
> > > --null makes grep output an ASCII NUL byte after the file name, so a
> > > program can parse the output of grep unambiguously even when the file
> > > names contains "funny" characters, such as a newline.
> > >
> > > GNU grep isn't the only one with a --null flag, also FreeBSD and NetBSD
> > > grep do (at least by looking at their manpages), so it's somewhat
> > > widespread.
> > >
> > > I searched the archives on marc.info but I haven't seen a previous
> > > discussion about this.
> > >
> > > The following patch was tried against GNU grep (installed from packages)
> > > and seem to behave consistently.
> > >
> > > I used the same text of the FreeBSD/NetBSD manpage for the description
> > > of the --null option, but I really dislike it: it feels way to verbose
> > > for what it's trying to say, but I wasn't able to come up with something
> > > better.
> > >
> > > I'm not familiar at all with the grep codebase, so I hope I'm not
> > > missing something. If this has some chances of being accepted, I guess
> > > I should also add some regress test; I'll try to work on them soon, but
> > > in the meantime I'm sending this.
> > >
> > > Thanks,
> > >
> > > Omar Polo
> >
> >
> > diff e992327fc31d0277a6f8518613a7db1b9face78b /home/op/w/openbsd-src
> > blob - 5cc228df222c54a0553f289b5da8bbbe6afd171e
> > file + usr.bin/grep/grep.1
> > --- usr.bin/grep/grep.1
> > +++ usr.bin/grep/grep.1
> > @@ -49,6 +49,7 @@
> > .Op Fl -context Ns Op = Ns Ar num
> > .Op Fl -label Ns = Ns Ar name
> > .Op Fl -line-buffered
> > +.Op Fl -null
> > .Op Ar pattern
> > .Op Ar
> > .Ek
> > @@ -297,6 +298,25 @@ instead of the filename before lines.
> > Force output to be line buffered.
> > By default, output is line buffered when standard output is a terminal
> > and block buffered otherwise.
> > +.It Fl -null
> > +Output a zero byte (the ASCII NUL character) instead of the character
> > +that normally follows a file name.
> > +For example,
> > +.Nm Fl l Fl -null
> > +outputs a zero byte after each file name instead of the usual newline.
> > +This option makes the output unambiguous, even in the presence of file
> > +names containing unusual characters like newlines.
> > +This option can be used with commands like
> > +.Xr find 1
> > +.Fl print0 Ns ,
> > +.Xr perl 1
> > +.Fl 0 Ns ,
> > +.Xr sort 1
> > +.Fl z Ns , and
> > +.Xr args 1
> > +.Fl 0
> > +to process arbitrary file names, even those that contain newline
> > +characters.
> > .El
> > .Sh EXIT STATUS
> > The
> > blob - f41b5e20ca68c9e9a36d2f7dd3c44329c621f29b
> > file + usr.bin/grep/grep.c
> > --- usr.bin/grep/grep.c
> > +++ usr.bin/grep/grep.c
> > @@ -80,6 +80,7 @@ int vflag; /* -v: only show non-matching
> > lines */
> > int wflag; /* -w: pattern must start and end on word
> > boundaries */
> > int xflag; /* -x: pattern must match entire line */
> > int lbflag; /* --line-buffered */
> > +int nullflag; /* --null */
> > const char *labelname; /* --label=name */
> >
> > int binbehave = BIN_FILE_BIN;
> > @@ -89,6 +90,7 @@ enum {
> > HELP_OPT,
> > MMAP_OPT,
> > LINEBUF_OPT,
> > + NULL_OPT,
> > LABEL_OPT,
> > };
> >
> > @@ -134,6 +136,7 @@ static const struct option long_options[] =
> > {"mmap", no_argument, NULL, MMAP_OPT},
> > {"label", required_argument, NULL, LABEL_OPT},
> > {"line-buffered", no_argument, NULL, LINEBUF_OPT},
> > + {"null", no_argument, NULL, NULL_OPT},
> > {"after-context", required_argument, NULL, 'A'},
> > {"before-context", required_argument, NULL, 'B'},
> > {"context", optional_argument, NULL, 'C'},
> > @@ -436,6 +439,9 @@ main(int argc, char *argv[])
> > case LINEBUF_OPT:
> > lbflag = 1;
> > break;
> > + case NULL_OPT:
> > + nullflag = 1;
> > + break;
> > case HELP_OPT:
> > default:
> > usage();
> > blob - b3d24ae662beb72c5632190c5c819bcc92f0389a
> > file + usr.bin/grep/grep.h
> > --- usr.bin/grep/grep.h
> > +++ usr.bin/grep/grep.h
> > @@ -68,7 +68,7 @@ extern int cflags, eflags;
> > extern int Aflag, Bflag, Eflag, Fflag, Hflag, Lflag,
> > Rflag, Zflag,
> > bflag, cflag, hflag, iflag, lflag, mflag, nflag, oflag, qflag,
> > - sflag, vflag, wflag, xflag;
> > + sflag, vflag, wflag, xflag, nullflag;
> > extern int binbehave;
> > extern const char *labelname;
> >
> > blob - e16d08e7d859609c2ccbc0ac4bba670188f81abf
> > file + usr.bin/grep/util.c
> > --- usr.bin/grep/util.c
> > +++ usr.bin/grep/util.c
> > @@ -172,13 +172,13 @@ procfile(char *fn)
> >
> > if (cflag) {
> > if (!hflag)
> > - printf("%s:", ln.file);
> > + printf("%s%c", ln.file, nullflag ? '\0' : ':');
> > printf("%llu%s\n", c, overflow ? "+" : "");
> > }
> > if (lflag && c != 0)
> > - printf("%s\n", fn);
> > + printf("%s%c", fn, nullflag ? '\0' : '\n');
> > if (Lflag && c == 0)
> > - printf("%s\n", fn);
> > + printf("%s%c", fn, nullflag ? '\0' : '\n');
> > if (c && !cflag && !lflag && !Lflag &&
> > binbehave == BIN_FILE_BIN && nottext && !qflag)
> > printf("Binary file %s matches\n", fn);
> > @@ -266,9 +266,9 @@ print:
> > if (Bflag > 0)
> > printqueue();
> > linesqueued = 0;
> > - printline(l, ':', oflag ? &pmatch : NULL);
> > + printline(l, nullflag ? '\0' : ':', oflag ? &pmatch :
> > NULL);
> > } else {
> > - printline(l, '-', oflag ? &pmatch : NULL);
> > + printline(l, nullflag ? '\0' : '-', oflag ? &pmatch :
> > NULL);
> > tail--;
> > }
> > }
> > @@ -660,7 +660,7 @@ printline(str_t *line, int sep, regmatch_t *pmatch)
> > }
> > if (nflag) {
> > if (n)
> > - putchar(sep);
> > + putchar(nullflag ? '\0' : sep);
> > printf("%lld", line->line_no);
> > ++n;
> > }
> >
> >
>
