Add the "columns(str)" variant.

examples/alignment.rem

@@ -0,0 +1,18 @@
+# Demo the columns() function
+#
+# Run as:  remind -@2 alignment.rem
+
+SET $AddBlankLines 0
+BANNER %
+
+FSET center(x) pad("", " ", (columns() - columns(x))/2) + x
+FSET right(x) pad("", " ", columns() - columns(x)) + x
+
+MSG This is left-aligned.
+MSG [ansicolor(0,255,0)]This is also left-aligned.[ansicolor("")]
+
+MSG [center("This is centered.")]
+MSG [ansicolor(0,255,0) + center("🌕 🌕 🌕 🌕 This is also centered. ") + ansicolor("")]
+
+msg [right("This is right-aligned.")]
+msg [ansicolor(0,255,0) + right("This is also right-aligned. 🌕 🌕 🌕") + ansicolor("")]

man/remind.1.in

@@ -2828,10 +2828,21 @@ above.  A \fBSTRING\fR \fIarg\fR is converted by parsing it as an
 integer.
 .RE
 .TP
-.B columns()
+.B columns([s_arg])
+If called with no arguments, \fBcolumns()\fR behaves as follows:
 If standard output is a TTY, returns the width of the terminal in columns.
 If standard output is not a TTY, attempts to open "/dev/tty" to obtain
 the terminal size.  If this fails, returns -1.
+.RS
+.PP
+If called with a single string argument, \fBcolumns(str)\fR returns
+the number of columns \fBstr\fR will occupy if printed to a terminal.
+ANSI color-changing sequences occupy zero columns whereas some Unicode
+characters occupy two columns.  \fBcolumns(str)\fR takes all of that
+into account.  Note that if Remind was compiled without Unicode support,
+\fBcolumns(str)\fR returns a type mismatch error.
+.RE
+
 .TP
 .B current()
 Returns the current date and time as a DATETIME object.  This may be the

src/calendar.c

@@ -9,7 +9,7 @@
 /*                                                             */
 /***************************************************************/
 
-#define _XOPEN_SOURCE
+#define _XOPEN_SOURCE 600
 #include "config.h"
 #include "custom.h"
 

src/funcs.c

@@ -13,6 +13,12 @@
 #include "version.h"
 #include "config.h"
 
+#ifdef REM_USE_WCHAR
+#define _XOPEN_SOURCE 600
+#include <wctype.h>
+#include <wchar.h>
+#endif
+
 #include <stdio.h>
 
 #include <stdlib.h>
@@ -230,7 +236,7 @@ BuiltinFunc Func[] = {
     {   "char",         1,      NO_MAX, 1,          FChar   },
     {   "choose",       2,      NO_MAX, 1,          FChoose },
     {   "coerce",       2,      2,      1,          FCoerce },
-    {   "columns",      0,      0,      0,          FColumns },
+    {   "columns",      0,      1,      0,          FColumns },
     {   "current",      0,      0,      0,          FCurrent },
     {   "date",         3,      3,      1,          FDate   },
     {   "datepart",     1,      1,      1,          FDatepart },
@@ -3409,5 +3415,44 @@ static int FRows(func_info *info)
 }
 static int FColumns(func_info *info)
 {
-    return rows_or_cols(info, 0);
+#ifdef REM_USE_WCHAR
+    size_t len;
+    wchar_t *buf, *s;
+    int width;
+#endif
+    if (Nargs == 0) {
+        return rows_or_cols(info, 0);
+    }
+    ASSERT_TYPE(0, STR_TYPE);
+#ifdef REM_USE_WCHAR
+    len = mbstowcs(NULL, ARGSTR(0), 0);
+    if (len == (size_t) -1) return E_NO_MEM;
+    buf = calloc(len+1, sizeof(wchar_t));
+    if (!buf) return E_NO_MEM;
+    (void) mbstowcs(buf, ARGSTR(0), len+1);
+
+    s = buf;
+    width = 0;
+    while (*s) {
+        if (*s == 0x1B && *(s+1) == '[') {
+            /* Skip escape sequences */
+            s += 2;
+            while (*s && (*s < 0x40 || *s > 0x7E)) {
+                s++;
+            }
+            if (*s) {
+                s++;
+            }
+            continue;
+        }
+        width += wcwidth(*s);
+        s++;
+    }
+    free(buf);
+    RetVal.type = INT_TYPE;
+    RETVAL = width;
+    return OK;
+#else
+    return E_BAD_TYPE;
+#endif
 }

src/main.c

@@ -10,7 +10,7 @@
 /*                                                             */
 /***************************************************************/
 
-#define _XOPEN_SOURCE
+#define _XOPEN_SOURCE 600
 #include "config.h"
 
 #include <errno.h>

src/protos.h

@@ -178,7 +178,7 @@ int have_callstack(void);
 int print_callstack(FILE *fp);
 void pop_call(void);
 #ifdef REM_USE_WCHAR
-#define _XOPEN_SOURCE
+#define _XOPEN_SOURCE 600
 #include <wctype.h>
 #include <wchar.h>
 void PutWideChar(wchar_t const wc);

tests/ansicolors.rem

@@ -42,3 +42,8 @@ set a ansicolor(128, 128, 128, -1)
 set a ansicolor(128, 128, 128, 0, 2)
 set a ansicolor(128, 128, 128, 0, -1)
 
+set a ansicolor(128,0,0)
+
+set str a + "foo: 🌅"
+set w columns(str)
+MSG Width of [str] is: [w]

tests/test.cmp

@@ -5568,6 +5568,8 @@ keyword will wrap it so it's pleasantly readable.
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: -1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -5629,6 +5631,8 @@ keyword will wrap it so
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: -1
 UseVTColors is:         1
 Use256Colors is:        1
@@ -5690,6 +5694,8 @@ keyword will wrap it[
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: -1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -5751,6 +5757,8 @@ keyword will[38;2;0
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 0
 UseVTColors is:         1
 Use256Colors is:        0
@@ -5812,6 +5820,8 @@ keyword will wrap it so
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 0
 UseVTColors is:         1
 Use256Colors is:        1
@@ -5873,6 +5883,8 @@ keyword will wrap it[
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 0
 UseVTColors is:         1
 Use256Colors is:        0
@@ -5934,6 +5946,8 @@ keyword will[38;2;0
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -5995,6 +6009,8 @@ keyword will wrap it so
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 1
 UseVTColors is:         1
 Use256Colors is:        1
@@ -6056,6 +6072,8 @@ keyword will wrap it[
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6117,6 +6135,8 @@ keyword will[38;2;0
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: -1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6178,6 +6198,8 @@ keyword will wrap it so
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: -1
 UseVTColors is:         1
 Use256Colors is:        1
@@ -6239,6 +6261,8 @@ keyword will wrap it[
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: -1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6300,6 +6324,8 @@ keyword will[38;2;0
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 0
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6361,6 +6387,8 @@ keyword will wrap it so
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 0
 UseVTColors is:         1
 Use256Colors is:        1
@@ -6422,6 +6450,8 @@ keyword will wrap it[
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 0
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6483,6 +6513,8 @@ keyword will[38;2;0
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6544,6 +6576,8 @@ keyword will wrap it so
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 1
 UseVTColors is:         1
 Use256Colors is:        1
@@ -6605,6 +6639,8 @@ keyword will wrap it[
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 TerminalBackground  is: 1
 UseVTColors is:         1
 Use256Colors is:        0
@@ -6666,6 +6702,8 @@ keyword will[38;2;0
 ../tests/ansicolors.rem(41): ansicolor(): Number too low
 ../tests/ansicolors.rem(42): ansicolor(): Number too high
 ../tests/ansicolors.rem(43): ansicolor(): Number too low
+Width of foo: 🌅 is: 7
+
 $AddBlankLines test
 Reminders for Saturday, 1st January, 2022: