add ncdirect_detected_terminal() and notcurses_detected_terminal() #1759

NEWS.md

@@ -32,6 +32,7 @@ rearrangements of Notcurses.
     could be in another pile. An error will instead be returned.
   * Fixed a bug in `ncdirect_box()` where default/palette-indexed colors
     weren't properly used on the top and bottom borders.
+  * Added `notcurses_detected_terminal()` and `ncdirect_detected_terminal()`.
 
 * 2.3.2 (2021-06-03)
   * Fixed a bug affecting certain scalings of `ncvisual` objects created from

doc/man/man3/notcurses_capabilities.3.md

@@ -10,6 +10,8 @@ notcurses_capabilities - runtime capability detection
 
 **#include <notcurses/notcurses.h>**
 
+**const char* notcurses_detected_terminal(const struct notcurses* ***nc***);**
+
 **unsigned notcurses_supported_styles(const struct notcurses* ***nc***);**
 
 **unsigned notcurses_palette_size(const struct notcurses* ***nc***);**
@@ -38,6 +40,16 @@ notcurses_capabilities - runtime capability detection
 
 # DESCRIPTION
 
+**notcurses_detected_terminal** returns a free-form string describing
+the detected terminal. Terminal detection takes into account any
+specified terminal database (see **notcurses_init(3)**), the **TERM**,
+**TERM_PROGRAM**, and **TERM_PROGRAM_VERSION** environment variables,
+the response to a **XTGETTCAP[TN]** Device Control String, the response
+to Primary, Secondary, and Tertiary Send Device Attributes control
+sequences, and the phase of the moon. You should not build logic around
+this response; all relevant properties of the terminal ought be
+abstracted by Notcurses. This is only made available for diagnostics.
+
 **notcurses_supported_styles** returns a bitmask representing those styles
 for which the terminal advertises support.
 

doc/man/man3/notcurses_direct.3.md

@@ -72,6 +72,8 @@ notcurses_direct - minimal notcurses instances for styling text
 
 **int ncdirect_printf_aligned(struct ncdirect* ***n***, int ***y***, ncalign_e ***align***, const char* ***fmt***, ***...***);**
 
+**const char* ncdirect_detected_terminal(const struct ncdirect* ***n***);**
+
 **bool ncdirect_canopen_images(const struct ncdirect* ***n***);**
 
 **bool ncdirect_canutf8(const struct ncdirect* ***n***);**

include/notcurses/direct.h

@@ -235,6 +235,9 @@ API int ncdirect_cursor_pop(struct ncdirect* n)
 API int ncdirect_clear(struct ncdirect* nc)
   __attribute__ ((nonnull (1)));
 
+API const char* ncdirect_detected_terminal(const struct ncdirect* n)
+  __attribute__ ((nonnull (1)));
+
 // Can we load images? This requires being built against FFmpeg/OIIO.
 API bool ncdirect_canopen_images(const struct ncdirect* n)
   __attribute__ ((nonnull (1)));

include/notcurses/notcurses.h

@@ -1242,21 +1242,29 @@ API bool ncplane_set_scrolling(struct ncplane* n, bool scrollp);
 // (NCSTYLE_UNDERLINE, NCSTYLE_BOLD, etc.) The attribute is only
 // indicated as supported if the terminal can support it together with color.
 // For more information, see the "ncv" capability in terminfo(5).
-API unsigned notcurses_supported_styles(const struct notcurses* nc);
+API unsigned notcurses_supported_styles(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Returns the number of simultaneous colors claimed to be supported, or 1 if
 // there is no color support. Note that several terminal emulators advertise
 // more colors than they actually support, downsampling internally.
-API unsigned notcurses_palette_size(const struct notcurses* nc);
+API unsigned notcurses_palette_size(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
+
+API const char* notcurses_detected_terminal(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we directly specify RGB values per cell, or only use palettes?
-API bool notcurses_cantruecolor(const struct notcurses* nc);
+API bool notcurses_cantruecolor(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we fade? Fading requires either the "rgb" or "ccc" terminfo capability.
-API bool notcurses_canfade(const struct notcurses* nc);
+API bool notcurses_canfade(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we set the "hardware" palette? Requires the "ccc" terminfo capability.
-API bool notcurses_canchangecolor(const struct notcurses* nc);
+API bool notcurses_canchangecolor(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we load images? This requires being built against FFmpeg/OIIO.
 API bool notcurses_canopen_images(const struct notcurses* nc);
@@ -1265,24 +1273,30 @@ API bool notcurses_canopen_images(const struct notcurses* nc);
 API bool notcurses_canopen_videos(const struct notcurses* nc);
 
 // Is our encoding UTF-8? Requires LANG being set to a UTF8 locale.
-API bool notcurses_canutf8(const struct notcurses* nc);
+API bool notcurses_canutf8(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we reliably use Unicode halfblocks?
-API bool notcurses_canhalfblock(const struct notcurses* nc);
+API bool notcurses_canhalfblock(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we reliably use Unicode quadrants?
-API bool notcurses_canquadrant(const struct notcurses* nc);
+API bool notcurses_canquadrant(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we reliably use Unicode 13 sextants?
-API bool notcurses_cansextant(const struct notcurses* nc);
+API bool notcurses_cansextant(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // Can we reliably use Unicode Braille?
-API bool notcurses_canbraille(const struct notcurses* nc);
+API bool notcurses_canbraille(const struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // This function must successfully return before NCBLIT_PIXEL is available.
 // Returns -1 on error, 0 for no support, or 1 if pixel output is supported.
 // Must not be called concurrently with either input or rasterization.
-API int notcurses_check_pixel_support(struct notcurses* nc);
+API int notcurses_check_pixel_support(struct notcurses* nc)
+  __attribute__ ((nonnull (1)));
 
 // whenever a new field is added here, ensure we add the proper rule to
 // notcurses_stats_reset(), so that values are preserved in the stash stats.

src/fetch/main.c

@@ -32,8 +32,8 @@ typedef struct fetched_info {
   char* kernel;                // strdup(uname(2)->name)
   char* kernver;               // strdup(uname(2)->version);
   char* desktop;               // getenv("XDG_CURRENT_DESKTOP")
-  char* shell;                 // getenv("SHELL")
-  char* term;                  // getenv("TERM")
+  const char* shell;           // getenv("SHELL")
+  const char* term;            // ncdirect_detected_terminal()
   char* lang;                  // getenv("LANG")
   int dimy, dimx;              // extracted from xrandr
   char* cpu_model;             // FIXME don't handle hetero setups yet
@@ -49,10 +49,10 @@ free_fetched_info(fetched_info* fi){
 }
 
 static int
-fetch_env_vars(fetched_info* fi){
+fetch_env_vars(struct ncdirect* nc, fetched_info* fi){
   fi->desktop = getenv("XDG_CURRENT_DESKTOP");
   fi->shell = getenv("SHELL");
-  fi->term = getenv("TERM");
+  fi->term = ncdirect_detected_terminal(nc);
   fi->lang = getenv("LANG");
   return 0;
 }
@@ -628,7 +628,7 @@ ncneofetch(struct ncdirect* nc){
   const bool launched = !pthread_create(&tid, NULL, display_thread, &display_marshal);
   unix_gethostname(&fi);
   unix_getusername(&fi);
-  fetch_env_vars(&fi);
+  fetch_env_vars(nc, &fi);
   fetch_x_props(&fi);
   if(kern == NCNEO_LINUX){
     fetch_cpu_info(&fi);

src/lib/direct.c

@@ -1368,3 +1368,7 @@ int ncdirectf_geom(ncdirect* n, ncdirectf* frame,
 unsigned ncdirect_supported_styles(const ncdirect* nc){
   return term_supported_styles(&nc->tcache);
 }
+
+const char* ncdirect_detected_terminal(const ncdirect* nc){
+  return nc->tcache.termname;
+}

src/lib/notcurses.c

@@ -858,12 +858,12 @@ init_banner_warnings(const notcurses* nc, FILE* out){
 // unless the suppress_banner flag was set, print some version information and
 // (if applicable) warnings to stdout. we are not yet on the alternate screen.
 static void
-init_banner(const notcurses* nc, const char* shortname_term){
+init_banner(const notcurses* nc){
   if(!nc->suppress_banner){
     char prefixbuf[BPREFIXSTRLEN + 1];
     term_fg_palindex(nc, stdout, 50 % nc->tcache.colors);
     printf("\n notcurses %s by nick black et al", notcurses_version());
-    printf(" on %s", shortname_term ? shortname_term : "?");
+    printf(" on %s", nc->tcache.termname ? nc->tcache.termname : "?");
     term_fg_palindex(nc, stdout, 12 % nc->tcache.colors);
     if(nc->tcache.cellpixy && nc->tcache.cellpixx){
       printf("\n  %d rows (%dpx) %d cols (%dpx) (%sB) %zuB crend %d colors",
@@ -1127,7 +1127,7 @@ notcurses* notcurses_core_init(const notcurses_options* opts, FILE* outfp){
     goto err;
   }
   ret->rstate.x = ret->rstate.y = -1;
-  init_banner(ret, shortname_term);
+  init_banner(ret);
   // flush on the switch to alternate screen, lest initial output be swept away
   const char* clearscr = get_escape(&ret->tcache, ESCAPE_CLEAR);
   if(ret->ttyfd >= 0){
@@ -1652,6 +1652,10 @@ unsigned notcurses_palette_size(const notcurses* nc){
   return nc->tcache.colors;
 }
 
+const char* notcurses_detected_terminal(const notcurses* nc){
+  return nc->tcache.termname;
+}
+
 bool notcurses_cantruecolor(const notcurses* nc){
   return nc->tcache.RGBflag;
 }

src/lib/termdesc.c

@@ -86,6 +86,7 @@ apply_term_heuristics(tinfo* ti, const char* termname, int fd){
   }
   ti->braille = true; // most everyone has working braille, even from fonts
   if(strstr(termname, "kitty")){ // kitty (https://sw.kovidgoyal.net/kitty/)
+    termname = "Kitty";
     // see https://sw.kovidgoyal.net/kitty/protocol-extensions.html
     // FIXME detect the actual default background color; this assumes it to
     // be RGB(0, 0, 0) (the default). we could also just set it, i guess.
@@ -96,20 +97,25 @@ apply_term_heuristics(tinfo* ti, const char* termname, int fd){
     ti->RGBflag = true;
     setup_kitty_bitmaps(ti, fd);
   }else if(strstr(termname, "alacritty")){
+    termname = "Alacritty";
     ti->alacritty_sixel_hack = true;
     ti->quadrants = true;
     // ti->sextants = true; // alacritty https://github.com/alacritty/alacritty/issues/4409 */
     ti->RGBflag = true;
   }else if(strstr(termname, "vte") || strstr(termname, "gnome") || strstr(termname, "xfce")){
+    termname = "VTE";
     ti->sextants = true; // VTE has long enjoyed good sextant support
     ti->quadrants = true;
   }else if(strncmp(termname, "foot", 4) == 0){
+    termname = "foot";
     ti->sextants = true;
     ti->quadrants = true;
     ti->RGBflag = true;
   }else if(strncmp(termname, "st", 2) == 0){
+    termname = "simple terminal";
     // st had neithersextants nor quadrants last i checked (0.8.4)
   }else if(strstr(termname, "mlterm")){
+    termname = "MLterm";
     ti->quadrants = true; // good quadrants, no sextants as of 3.9.0
     ti->sprixel_cursor_hack = true;
   }else if(strstr(termname, "xterm")){
@@ -117,7 +123,21 @@ apply_term_heuristics(tinfo* ti, const char* termname, int fd){
     // of people using xterm when they shouldn't be, or even real database
     // entries like "xterm-kitty" (if we don't catch them above), giving a
     // pretty minimal (but safe) experience. set your TERM correctly!
+    // wezterm wants a TERM of xterm-256color, and identifies itself based
+    // off TERM_PROGRAM and TERM_PROGRAM_VERSION.
+    const char* term_program = getenv("TERM_PROGRAM");
+    if(term_program && strcmp(term_program, "WezTerm") == 0){
+      termname = "WezTerm";
+      ti->quadrants = true;
+      const char* termver = getenv("TERM_PROGRAM_VERSION");
+      if(termver && strcmp(termver, "20210610") >= 0){
+        ti->sextants = true; // good sextants as of 2021-06-10
+      }
+    }else{
+      termname = "XTerm";
+    }
   }else if(strcmp(termname, "linux") == 0){
+    termname = "Linux console";
     ti->braille = false; // no braille, no sextants in linux console
     // FIXME if the NCOPTION_NO_FONT_CHANGES, this isn't true
     // FIXME we probably want to do this based off ioctl()s in linux.c
@@ -131,6 +151,7 @@ apply_term_heuristics(tinfo* ti, const char* termname, int fd){
   if(wcwidth(L'🬸') < 0){
     ti->sextants = false;
   }
+  ti->termname = termname;
   return 0;
 }
 

src/lib/termdesc.h

@@ -118,6 +118,7 @@ typedef struct tinfo {
   int (*pixel_shutdown)(int fd);  // called during context shutdown
   int (*pixel_clear_all)(int fd); // called during startup, kitty only
   int sprixel_scale_height; // sprixel must be a multiple of this many rows
+  const char* termname;     // determined terminal name
   struct termios tpreserved; // terminal state upon entry
   ncinputlayer input;       // input layer
   bool bitmap_supported;    // do we support bitmaps (post pixel_query_done)?