[dev] [sbase] [PATCH] ls: add option to reverse the sort order

[Markus Teich]

Now you can list directory contents ordered by mtime with the latest file
displayed last in the output.
---
 ls.1 | 3 +++
 ls.c | 8 ++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/ls.1 b/ls.1
index 00ae32b..f10c929 100644
--- a/ls.1
+++ b/ls.1
@@ -21,6 +21,9 @@ lists directories themselves, not their contents.
 lists detailed information about each file, including their type, permissions,
 links, owner, group, size, and modification time.
 .TP
+.B \-r
+reverses the sort order.
+.TP
 .B \-t
 sorts files by modification time instead of by name.
 .TP
diff --git a/ls.c b/ls.c
index f61d7c5..db8742c 100644
--- a/ls.c
+++ b/ls.c
@@ -33,6 +33,7 @@ static bool dflag = false;
 static bool lflag = false;
 static bool tflag = false;
 static bool Uflag = false;
+static int sortorder = 1;
 static bool first = true;
 static bool many;
 
@@ -58,6 +59,9 @@ main(int argc, char *argv[])
        case 'l':
                lflag = true;
                break;
+       case 'r':
+               sortorder = -1;
+               break;
        case 't':
                tflag = true;
                break;
@@ -89,9 +93,9 @@ entcmp(const void *va, const void *vb)
        const Entry *a = va, *b = vb;
 
        if(tflag)
-               return b->mtime - a->mtime;
+               return sortorder * (b->mtime - a->mtime);
        else
-               return strcmp(a->name, b->name);
+               return sortorder * (strcmp(a->name, b->name));
 }
 
 void
-- 
1.8.2