Commit 3654b370 authored by Jonas Termansen's avatar Jonas Termansen

Add -R option to sort(1).

parent a209c892
......@@ -6,7 +6,7 @@
.Nd sort lines of text
.Sh SYNOPSIS
.Nm
.Op Fl CcmruVz
.Op Fl CcmRruVz
.Op Fl o Ar path
.Ar
.Sh DESCRIPTION
......@@ -46,6 +46,16 @@ This option is incompatible with
.Fl C
and
.Fl c .
.It Fl R , \-random-sort
Sort the lines randomly with an uniform distribution, where all permutations are
equally likely.
This option is incompatible with
.Fl C
and
.Fl c .
If
.Fl u ,
don't write duplicate lines to the output.
.It Fl r , \-reverse
Compare the lines in reverse order.
.It Fl u , \-unique
......@@ -123,12 +133,18 @@ which is currently partially implemented in this implementation of
.Nm .
.Pp
The
.Fl V
.Fl R , V ,
and
.Fl z
options, as well as the long options, are extensions also found in GNU
coreutils.
.Pp
Unlike GNU coreutils,
.Fl R
will not remove duplicates unless
.Fl u
is passed.
.Pp
As an extension, the
.Fl C
and
......
......@@ -29,6 +29,17 @@
// TODO: Implement all the features mandated by POSIX.
// TODO: Implement the useful GNU extensions.
static size_t pick_uniform(size_t upper)
{
if ( upper < 2 )
return 0;
size_t minimum = -upper % upper;
size_t selection;
do arc4random_buf(&selection, sizeof(selection));
while ( selection < minimum );
return selection % upper;
}
static int flip_comparison(int rel)
{
return rel < 0 ? 1 : 0 < rel ? -1 : 0;
......@@ -194,6 +205,7 @@ int main(int argc, char* argv[])
bool check_quiet = false;
bool merge = false;
const char* output = NULL;
bool random = false;
bool reverse = false;
bool unique = false;
bool version_sort = false;
......@@ -225,6 +237,7 @@ int main(int argc, char* argv[])
}
arg = "o";
break;
case 'R': random = true; break;
case 'r': reverse = true; break;
case 'u': unique = true; break;
case 'V': version_sort = true; break;
......@@ -250,6 +263,8 @@ int main(int argc, char* argv[])
output = argv[i+1];
argv[++i] = NULL;
}
else if ( !strcmp(arg, "--random-sort") )
random = true;
else if ( !strcmp(arg, "--reverse") )
reverse = true;
else if ( !strcmp(arg, "--unique") )
......@@ -268,6 +283,10 @@ int main(int argc, char* argv[])
errx(1, "the -C and -o options are incompatible");
if ( check && output )
errx(1, "the -c and -o options are incompatible");
if ( check_quiet && random )
errx(1, "the -C and -R options are incompatible");
if ( check && random )
errx(1, "the -c and -R options are incompatible");
int delim = zero_terminated ? '\0' : '\n';
......@@ -319,7 +338,34 @@ int main(int argc, char* argv[])
size_t lines_used = 0;
char** lines = read_input_stream_lines(&lines_used, &is, delim);
qsort(lines, lines_used, sizeof(*lines), qsort_compare);
if ( !random || unique )
qsort(lines, lines_used, sizeof(*lines), qsort_compare);
if ( random )
{
if ( unique )
{
size_t o = 0;
for ( size_t i = 0; i < lines_used; i++ )
{
if ( o && compare(lines[i], lines[o - 1]) == 0 )
continue;
lines[o++] = lines[i];
}
lines_used = o;
}
for ( size_t i = 0; i < lines_used; i++ )
{
size_t left = lines_used - i;
size_t choice = i + pick_uniform(left);
if ( choice != i )
{
char* tmp = lines[i];
lines[i] = lines[choice];
lines[choice] = tmp;
}
}
}
if ( output && !freopen(output, "w", stdout) )
err(2, "%s", output);
......
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