Add --intr option.

NEWS

@@ -21,6 +21,8 @@
 
 * Add --modelines option (github #89).
 
+* Add --intr option (github #224).
+
 * Allow empty "lines" field in --header option.
 
 * Update Unicode tables.

less.hlp

@@ -217,10 +217,12 @@
  Use N lines and M columns to display file headers.
  --incsearch
  Search file as each pattern character is typed in.
- --line-num-width=N
- Set the width of the -N line number field to N characters.
- --modelines=N
- Read N lines from the input file and look for vim modelines.
+ --intr=_C
+ Use _C instead of ^X to interrupt a read.
+ --line-num-width=_N
+ Set the width of the -N line number field to _N characters.
+ --modelines=_N
+ Read _N lines from the input file and look for vim modelines.
  --mouse
  Enable mouse input.
  --no-keypad
@@ -235,22 +237,22 @@
  Disable the terminal's visual bell.
  --redraw-on-quit
  Redraw final screen when quitting.
- --rscroll=C
+ --rscroll=_C
  Set the character used to mark truncated lines.
  --save-marks
  Retain marks across invocations of less.
  --search-options=[EFKNRW-]
  Set default options for every search.
- --status-col-width=N
- Set the width of the -J status column to N characters.
+ --status-col-width=_N
+ Set the width of the -J status column to _N characters.
  --status-line
  Highlight or color the entire line containing a mark.
  --use-backslash
  Subsequent options use backslash as escape char.
  --use-color
  Enables colored text.
- --wheel-lines=N
- Each click of the mouse wheel moves N lines.
+ --wheel-lines=_N
+ Each click of the mouse wheel moves _N lines.
 
 
  ---------------------------------------------------------------------------

less.nro.VER

@@ -121,7 +121,7 @@ while it is being viewed.
 To stop waiting for more data, enter the interrupt character (usually \(haC).
 On systems which support
 .BR poll (1)
-you can also use \(haX.
+you can also use \(haX or the character specified by the \-\-intr option.
 If the input is a pipe and the \-\-exit-follow-on-close option is in effect,
 .B less
 will automatically stop waiting for data when the input side 
@@ -470,7 +470,9 @@ This may cause
 .B less
 to think that the file ends at the current position,
 so it may be necessary to use the R or F command to see more data.
-The \(haX command works only on systems that support the
+The \-\-intr option can be used to specify a different character
+to use instead of \(haX.
+This command works only on systems that support the
 .BR poll (1)
 function.
 On systems without
@@ -1174,6 +1176,13 @@ Subsequent search commands will be "incremental"; that is,
 .B less
 will advance to the next line containing the search pattern 
 as each character of the pattern is typed in.
+.IP "\-\-intr=\fIc\fP"
+Use the character \fIc\fP instead of \(haX to interrupt a read
+when the "Waiting for data" message is displayed.
+\fIc\fP must be an ASCII character; that is, one with a value 
+between 1 and 127 inclusive.
+A caret followed by a single character can be used 
+to specify a control character.
 .IP "\-\-line-num-width=\fIn\fP"
 Sets the minimum width of the line number field when the \-N option is in effect 
 to \fIn\fP characters.

lesstest/Makefile

@@ -1,4 +1,4 @@
-CC = gcc
+CC ?= gcc
 CFLAGS = -Wall -O2
 TERMLIB = -lncurses
 

optfunc.c

@@ -66,6 +66,7 @@ extern int chopline;
 extern int tabstops[];
 extern int ntabstops;
 extern int tabdefault;
+extern char intr_char;
 #if LOGFILE
 extern char *namelogfile;
 extern int force_logfile;
@@ -793,7 +794,7 @@ public void opt_rscroll(int type, char *s)
  break; }
  case QUERY: {
  p.p_string = rscroll_char ? prchar(rscroll_char) : "-";
- error("rscroll char is %s", &p);
+ error("rscroll character is %s", &p);
  break; }
  }
 }
@@ -920,6 +921,29 @@ public void opt_filesize(int type, char *s)
  }
 }
 
+/*
+ * Handler for the --intr option.
+ */
+ /*ARGSUSED*/
+public void opt_intr(int type, char *s)
+{
+ PARG p;
+
+ switch (type)
+ {
+ case INIT:
+ case TOGGLE:
+ intr_char = *s;
+ if (intr_char == '^' && s[1] != '\0')
+ intr_char = CONTROL(s[1]);
+ break;
+ case QUERY: {
+ p.p_string = prchar(intr_char);
+ error("interrupt character is %s", &p);
+ break; }
+ }
+}
+
 /*
  * Handler for the --header option.
  */

opttbl.c

@@ -74,6 +74,7 @@ public int redraw_on_quit; /* Redraw last screen after term deinit */
 public int def_search_type; /* */
 public int exit_F_on_close; /* Exit F command when input closes */
 public int modelines; /* Lines to read looking for modelines */
+public char intr_char = CONTROL('X'); /* Char to interrupt reads */
 #if HILITE_SEARCH
 public int hilite_search; /* Highlight matched search patterns? */
 #endif
@@ -158,6 +159,7 @@ static struct optname search_type_optname = { "search-options", NULL };
 static struct optname exit_F_on_close_optname = { "exit-follow-on-close", NULL };
 static struct optname modelines_optname = { "modelines", NULL };
 static struct optname no_vbell_optname = { "no-vbell", NULL };
+static struct optname intr_optname = { "intr", NULL };
 #if LESSTEST
 static struct optname ttyin_name_optname = { "tty", NULL };
 #endif /*LESSTEST*/
@@ -506,7 +508,7 @@ static struct loption option[] =
  },
  { OLETTER_NONE, &rscroll_optname,
  STRING|REPAINT|INIT_HANDLER, 0, NULL, opt_rscroll,
- { "right scroll character: ", NULL, NULL }
+ { "rscroll character: ", NULL, NULL }
  },
  { OLETTER_NONE, &nohistdups_optname,
  BOOL, OPT_OFF, &no_hist_dups, NULL,
@@ -652,6 +654,10 @@ static struct loption option[] =
  NULL
  }
  },
+ { OLETTER_NONE, &intr_optname,
+ STRING, 0, NULL, opt_intr,
+ { "interrupt character: ", NULL, NULL }
+ },
 #if LESSTEST
  { OLETTER_NONE, &ttyin_name_optname,
  STRING|NO_TOGGLE, 0, NULL, opt_ttyin_name,

os.c

@@ -75,6 +75,7 @@ extern int sigs;
 extern int ignore_eoi;
 extern int exit_F_on_close;
 extern int follow_mode;
+extern char intr_char;
 #if !MSDOS_COMPILER
 extern int tty;
 #endif
@@ -111,7 +112,7 @@ static int check_poll(int fd, int tty)
  if (poller[1].revents & POLLIN) 
  {
  LWCHAR ch = getchr();
- if (ch == CONTROL('X'))
+ if (ch == intr_char)
  /* Break out of "waiting for data". */
  return (READ_INTR);
  ungetcc_back(ch);
@@ -223,7 +224,7 @@ public int iread(int fd, unsigned char *buf, unsigned int len)
  }
 #else
 #if MSDOS_COMPILER==WIN32C
- if (win32_kbhit() && WIN32getch() == CONTROL('X'))
+ if (win32_kbhit() && WIN32getch() == intr_char)
  {
  sigs |= S_INTERRUPT;
  reading = 0;

output.c

@@ -31,6 +31,7 @@ extern int so_s_width, so_e_width;
 extern int screen_trashed;
 extern int is_tty;
 extern int oldbot;
+extern char intr_char;
 
 #if MSDOS_COMPILER==WIN32C || MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
 extern int ctldisp;
@@ -661,33 +662,32 @@ public void error(char *fmt, PARG *parg)
  * Usually used to warn that we are beginning a potentially
  * time-consuming operation.
  */
-static void ierror_suffix(char *fmt, char *suffix, PARG *parg)
+static void ierror_suffix(char *fmt, PARG *parg, char *suffix1, char *suffix2, char *suffix3)
 {
  at_exit();
  clear_bot();
  at_enter(AT_STANDOUT|AT_COLOR_ERROR);
  (void) less_printf(fmt, parg);
- putstr(suffix);
+ putstr(suffix1);
+ putstr(suffix2);
+ putstr(suffix3);
  at_exit();
  flush();
  need_clr = 1;
 }
 
 public void ierror(char *fmt, PARG *parg)
 {
- static char suffix[] = "... (interrupt to abort)";
- ierror_suffix(fmt, suffix, parg);
+ ierror_suffix(fmt, parg, "... (interrupt to abort)", "", "");
 }
 
 public void ixerror(char *fmt, PARG *parg)
 {
  if (!supports_ctrl_x())
  ierror(fmt, parg);
  else
- {
- static char suffix[] = "... (^X or interrupt to abort)";
- ierror_suffix(fmt, suffix, parg);
- }
+ ierror_suffix(fmt, parg,
+ "... (", prchar(intr_char), " or interrupt to abort)");
 }
 
 /*

version.c

@@ -967,7 +967,7 @@ v616 12/9/22 Don't open tty as input file without -f.
 v617 12/10/22 Support poll on newer versions of MacOS.
 v618 12/29/22 Add --no-search-headers option; use C89 function definitions.
 v619 12/30/22 Fix bug using 'n' before '/'.
-v620 Add --modelines option.
+v620 Add --modelines option; add --intr option.
 */
 
 char version[] = "620x";