less: document -S flag and make it independently configurable

The -S flag, to cause long lines to be truncated, was enabled by
FEATURE_LESS_DASHCMD.  This is non-obvious and -S is useful even
if the '-' command isn't enabled.

function                                             old     new   delta
.rodata                                           156045  156077     +32
packed_usage                                       30223   30244     +21
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 53/0)               Total: 53 bytes

Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/miscutils/less.c b/miscutils/less.c
index d5a68d1e1..c1755655a 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -48,6 +48,14 @@
 //config:       help
 //config:         The -M/-m flag enables a more sophisticated status line.
 //config:
+//config:config FEATURE_LESS_TRUNCATE
+//config:       bool "Enable -S"
+//config:       default y
+//config:       depends on LESS
+//config:       help
+//config:         The -S flag causes long lines to be truncated rather than
+//config:         wrapped.
+//config:
 //config:config FEATURE_LESS_MARKS
 //config:       bool "Enable marks"
 //config:       default y
@@ -98,7 +106,8 @@
 //config:         Enables "-N" command.
 
 //usage:#define less_trivial_usage
-//usage:       "[-E" IF_FEATURE_LESS_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm") "Nh~] [FILE]..."
+//usage:       "[-E" IF_FEATURE_LESS_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm")
+//usage:       "N" IF_FEATURE_LESS_TRUNCATE("S") "h~] [FILE]..."
 //usage:#define less_full_usage "\n\n"
 //usage:       "View FILE (or stdin) one screenful at a time\n"
 //usage:     "\n        -E      Quit once the end of a file is reached"
@@ -110,6 +119,9 @@
 //usage:     "\n                and percentage through the file"
 //usage:        )
 //usage:     "\n        -N      Prefix line number to each line"
+//usage:        IF_FEATURE_LESS_TRUNCATE(
+//usage:     "\n        -S      Truncate long lines"
+//usage:        )
 //usage:     "\n        -~      Suppress ~s displayed past EOF"
 
 #include <sched.h>  /* sched_yield() */
@@ -144,7 +156,7 @@ enum {
         FLAG_N = 1 << 3,
         FLAG_TILDE = 1 << 4,
         FLAG_I = 1 << 5,
-        FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_DASHCMD,
+        FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_TRUNCATE,
 /* hijack command line options variable for internal state vars */
         LESS_STATE_MATCH_BACKWARDS = 1 << 15,
 };
@@ -820,7 +832,7 @@ static void buffer_print(void)
 static void buffer_fill_and_print(void)
 {
         unsigned i;
-#if ENABLE_FEATURE_LESS_DASHCMD
+#if ENABLE_FEATURE_LESS_TRUNCATE
         int fpos = cur_fline;
 
         if (option_mask32 & FLAG_S) {
@@ -1330,10 +1342,12 @@ static void flag_change(void)
         case '~':
                 option_mask32 ^= FLAG_TILDE;
                 break;
+#if ENABLE_FEATURE_LESS_TRUNCATE
         case 'S':
                 option_mask32 ^= FLAG_S;
                 buffer_fill_and_print();
                 break;
+#endif
 #if ENABLE_FEATURE_LESS_LINENUMS
         case 'N':
                 option_mask32 ^= FLAG_N;
@@ -1638,7 +1652,7 @@ int less_main(int argc, char **argv)
          * -s: condense many empty lines to one
          *     (used by some setups for manpage display)
          */
-        getopt32(argv, "EMmN~I" IF_FEATURE_LESS_DASHCMD("S") /*ignored:*/"s");
+        getopt32(argv, "EMmN~I" IF_FEATURE_LESS_TRUNCATE("S") /*ignored:*/"s");
         argc -= optind;
         argv += optind;
         num_files = argc;