From 677c1b5b4051288a75db1ec24ce38f0067ca80af Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Tue, 23 Dec 2014 13:29:47 -0600
Subject: Merge catv back into cat as discussed on the list. Add comments about
 infrastructure upgrades needed to restore separate catv option.

---
 toys/posix/cat.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 79 insertions(+), 6 deletions(-)

(limited to 'toys/posix/cat.c')

diff --git a/toys/posix/cat.c b/toys/posix/cat.c
index 3644c4f9..5b4ab71a 100644
--- a/toys/posix/cat.c
+++ b/toys/posix/cat.c
@@ -3,8 +3,12 @@
  * Copyright 2006 Rob Landley <rob@landley.net>
  *
  * See http://opengroup.org/onlinepubs/9699919799/utilities/cat.html
+ *
+ * And "Cat -v considered harmful" at
+ *   http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz
 
-USE_CAT(NEWTOY(cat, "u", TOYFLAG_BIN))
+USE_CAT(NEWTOY(cat, "u"USE_CAT_V("vte"), TOYFLAG_BIN))
+#USE_CATV(NEWTOY(catv, USE_CATV("vte"), TOYFLAG_USR|TOYFLAG_BIN))
 
 config CAT
   bool "cat"
@@ -16,19 +20,76 @@ config CAT
     Filename "-" is a synonym for stdin.
 
     -u	Copy one byte at a time (slow).
+
+config CAT_V
+  bool "cat -etv"
+  default y
+  depends on CAT
+  help
+    usage: cat [-evt]
+
+    Display nonprinting characters as escape sequences. Use M-x for
+
+    -e	Mark each newline with $
+    -t	Show tabs as ^I
+    -v	Display nonprinting characters as escape sequences. Use M-x for
+    	high ascii characters (>127), and ^x for other nonprinting chars.
+*/
+
+/*
+todo:
+
+config CATV
+  bool "catv"
+  default y
+  depends on !CAT_V
+  help
+    usage: catv [-evt] [filename...]
+
+    Display nonprinting characters as escape sequences. Use M-x for
+    high ascii characters (>127), and ^x for other nonprinting chars.
+
+    -e  Mark each newline with $
+    -t  Show tabs as ^I
+    -v  Don't use ^x or M-x escapes.
 */
 
+#define FOR_cat
 #include "toys.h"
 
 static void do_cat(int fd, char *name)
 {
-  int len, size=toys.optflags ? 1 : sizeof(toybuf);
+  int i, len, size=(toys.optflags & FLAG_u) ? 1 : sizeof(toybuf);
 
-  for (;;) {
+  for(;;) {
     len = read(fd, toybuf, size);
-    if (len<0) perror_msg("%s",name);
-    if (len<1) break;
-    xwrite(1, toybuf, len);
+    if (len < 0) toys.exitval = EXIT_FAILURE;
+    if (len < 1) break;
+    if (CFG_CAT_V && (toys.optflags&~FLAG_u)) {
+      for (i=0; i<len; i++) {
+        char c=toybuf[i];
+
+        if (c > 126 && (toys.optflags & FLAG_v)) {
+          if (c > 127) {
+            printf("M-");
+            c -= 128;
+          }
+          if (c == 127) {
+            printf("^?");
+            continue;
+          }
+        }
+        if (c < 32) {
+          if (c == 10) {
+            if (toys.optflags & FLAG_e) xputc('$');
+          } else if (toys.optflags & (c==9 ? FLAG_t : FLAG_v)) {
+            printf("^%c", c+'@');
+            continue;
+          }
+        }
+        xputc(c);
+      }
+    } else xwrite(1, toybuf, len);
   }
 }
 
@@ -36,3 +97,15 @@ void cat_main(void)
 {
   loopfiles(toys.optargs, do_cat);
 }
+
+//todo:
+//void catv_main(void)
+//{
+//  toys.optflags ^= FLAG_v;
+//  loopfiles(toys.optargs, do_catv);
+//}
+
+// The common infrastructure is testing FLAG_h which is only defined in cat
+// context (not catv), but catv can't use cat's flag context if cat is disabled
+// and its flags are zero. Need to upgrade flag parsing infrastructure so
+// defining FORCE_FLAGS along with FOR_command doesn't zero unused flag macros.
-- 
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