Index: src/bisect.c
==================================================================
--- src/bisect.c
+++ src/bisect.c
@@ -390,11 +390,11 @@
       for(i=0; i<sizeof(aBisectOption)/sizeof(aBisectOption[0]); i++){
         char *z = mprintf("bisect-%s", aBisectOption[i].zName);
         fossil_print("  %-15s  %-6s  ", aBisectOption[i].zName,
                db_lget(z, (char*)aBisectOption[i].zDefault));
         fossil_free(z);
-        comment_print(aBisectOption[i].zDesc, 27, 79);
+        comment_print(aBisectOption[i].zDesc, 27, -1);
       }
     }else if( g.argc==4 || g.argc==5 ){
       unsigned int i;
       n = strlen(g.argv[3]);
       for(i=0; i<sizeof(aBisectOption)/sizeof(aBisectOption[0]); i++){

Index: src/comformat.c
==================================================================
--- src/comformat.c
+++ src/comformat.c
@@ -19,10 +19,15 @@
 ** text on a TTY.
 */
 #include "config.h"
 #include "comformat.h"
 #include <assert.h>
+#ifdef _WIN32
+# include <windows.h>
+#else
+# include <termios.h>
+#endif
 
 /*
 ** Given a comment string zText, format that string for printing
 ** on a TTY.  Assume that the output cursors is indent spaces from
 ** the left margin and that a single line can contain no more than
@@ -36,10 +41,27 @@
   int doIndent = 0;
   char *zBuf;
   char zBuffer[400];
   int lineCnt = 0;
 
+#if defined(_WIN32)
+  if( lineLength<0 ){
+    CONSOLE_SCREEN_BUFFER_INFO csbi;
+    memset(&csbi, 0, sizeof(CONSOLE_SCREEN_BUFFER_INFO));
+    if( GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi) ){
+      tlen = csbi.srWindow.Right - csbi.srWindow.Left - indent;
+    }
+  }
+#elif defined(TIOCGWINSZ)
+  if( lineLength<0 ){
+    struct winsize w;
+    memset(&w, 0, sizeof(struct winsize));
+    if( ioctl(0, TIOCGWINSZ, &w)!=-1 ){
+      tlen = w.ws_col - indent;
+    }
+  }
+#endif
   if( zText==0 ) zText = "(NULL)";
   if( tlen<=0 ){
     tlen = strlen(zText);
   }
   if( tlen >= (sizeof(zBuffer)) ){

Index: src/descendants.c
==================================================================
--- src/descendants.c
+++ src/descendants.c
@@ -356,11 +356,11 @@
     width = atoi(zWidth);
     if( (width!=0) && (width<=39) ){
       fossil_fatal("-W|--width value must be >39 or 0");
     }
   }else{
-    width = 79;
+    width = -1;
   }
   db_find_and_open_repository(0,0);
   if( recomputeFlag ) leaf_rebuild();
   blob_zero(&sql);
   blob_append(&sql, timeline_query_for_tty(), -1);

Index: src/finfo.c
==================================================================
--- src/finfo.c
+++ src/finfo.c
@@ -146,16 +146,20 @@
       /* this is the default, no-op */
     }
     zLimit = find_option("limit","n",1);
     zWidth = find_option("width","W",1);
     iLimit = zLimit ? atoi(zLimit) : -1;
-    iWidth = zWidth ? atoi(zWidth) : 79;
     zOffset = find_option("offset",0,1);
     iOffset = zOffset ? atoi(zOffset) : 0;
     iBrief = (find_option("brief","b",0) == 0);
-    if( (iWidth!=0) && (iWidth<=22) ){
-      fossil_fatal("-W|--width value must be >22 or 0");
+    if( zWidth ){
+      iWidth = atoi(zWidth);
+      if( (iWidth!=0) && (iWidth<=22) ){
+        fossil_fatal("-W|--width value must be >22 or 0");
+      }
+    }else{
+      iWidth = -1;
     }
     if( g.argc!=3 ){
       usage("?-l|--log? ?-b|--brief? FILENAME");
     }
     file_tree_name(g.argv[2], &fname, 1);

Index: src/info.c
==================================================================
--- src/info.c
+++ src/info.c
@@ -132,11 +132,11 @@
     fossil_print("tags:         %s\n", zTags);
   }
   free(zTags);
   if( zComment ){
     fossil_print("comment:      ");
-    comment_print(zComment, 14, 79);
+    comment_print(zComment, 14, -1);
     free(zComment);
   }
 }
 
 /*

Index: src/merge.c
==================================================================
--- src/merge.c
+++ src/merge.c
@@ -47,11 +47,11 @@
        indent-1, zLabel,
        db_column_text(&q, 3),
        db_column_text(&q, 1),
        db_column_text(&q, 0),
        indent, "");
-    comment_print(zCom, indent, 78);
+    comment_print(zCom, indent, -1);
     fossil_free(zCom);
   }
   db_finalize(&q);
 }
 
@@ -210,11 +210,11 @@
     );
     if( db_step(&q)==SQLITE_ROW ){
       char *zCom = mprintf("Merging fork [%S] at %s by %s: \"%s\"",
             db_column_text(&q, 0), db_column_text(&q, 1),
             db_column_text(&q, 3), db_column_text(&q, 2));
-      comment_print(zCom, 0, 79);
+      comment_print(zCom, 0, -1);
       fossil_free(zCom);
     }
     db_finalize(&q);
   }else{
     usage("?OPTIONS? ?VERSION?");

Index: src/name.c
==================================================================
--- src/name.c
+++ src/name.c
@@ -582,11 +582,11 @@
       default:   zType = "Unknown";        break;
     }
     fossil_print("type:       %s by %s on %s\n", zType, db_column_text(&q,2),
                  db_column_text(&q, 1));
     fossil_print("comment:    ");
-    comment_print(db_column_text(&q,3), 12, 78);
+    comment_print(db_column_text(&q,3), 12, -1);
   }
   db_finalize(&q);
 
   /* Check to see if this object is used as a file in a check-in */
   db_prepare(&q,
@@ -604,11 +604,11 @@
     fossil_print("            part of [%.10s] by %s on %s\n",
       db_column_text(&q, 1),
       db_column_text(&q, 3),
       db_column_text(&q, 2));
     fossil_print("            ");
-    comment_print(db_column_text(&q,4), 12, 78);
+    comment_print(db_column_text(&q,4), 12, -1);
   }
   db_finalize(&q);
 
   /* Check to see if this object is used as an attachment */
   db_prepare(&q,
@@ -639,11 +639,11 @@
                    db_column_text(&q,7));
     }
     fossil_print("            by user %s on %s\n",
                  db_column_text(&q,2), db_column_text(&q,3));
     fossil_print("            ");
-    comment_print(db_column_text(&q,1), 12, 78);
+    comment_print(db_column_text(&q,1), 12, -1);
   }
   db_finalize(&q);
 }
 
 /*

Index: src/search.c
==================================================================
--- src/search.c
+++ src/search.c
@@ -202,11 +202,11 @@
     width = atoi(zWidth);
     if( (width!=0) && (width<=20) ){
       fossil_fatal("-W|--width value must be >20 or 0");
     }
   }else{
-    width = 79;
+    width = -1;
   }
 
   db_must_be_within_tree();
   if( g.argc<2 ) return;
   blob_init(&pattern, g.argv[2], -1);

Index: src/stash.c
==================================================================
--- src/stash.c
+++ src/stash.c
@@ -525,11 +525,11 @@
       width = atoi(zWidth);
       if( (width!=0) && (width<=46) ){
         fossil_fatal("-W|--width value must be >46 or 0");
       }
     }else{
-      width = 79;
+      width = -1;
     }
     if( !verboseFlag ){
       verboseFlag = find_option("detail","l",0)!=0; /* deprecated */
     }
     verify_all_options();

Index: src/timeline.c
==================================================================
--- src/timeline.c
+++ src/timeline.c
@@ -1780,11 +1780,11 @@
     width = atoi(zWidth);
     if( (width!=0) && (width<=20) ){
       fossil_fatal("-W|--width value must be >20 or 0");
     }
   }else{
-    width = 79;
+    width = -1;
   }
   zOffset = find_option("offset",0,1);
   iOffset = zOffset ? atoi(zOffset) : 0;
   if( g.argc>=4 ){
     k = strlen(g.argv[2]);

Index: src/tkt.c
==================================================================
--- src/tkt.c
+++ src/tkt.c
@@ -1264,11 +1264,11 @@
             fossil_print("  Change ");
           }
           fossil_print("%h: ",z);
           if( blob_size(&val)>50 || contains_newline(&val)) {
                   fossil_print("\n    ",blob_str(&val));
-                  comment_print(blob_str(&val),4,79);
+                  comment_print(blob_str(&val),4,-1);
                 }else{
                   fossil_print("%s\n",blob_str(&val));
                 }
                 blob_reset(&val);
               }