Add lua repl interface to redbean

You can now interact with the global web server state on the command
line, which the web server is running. This supports Emacs shortcuts
with history, readline parity, <tab> completions, plus hints. Enjoy!

third_party/linenoise/linenoise.c

@@ -122,7 +122,9 @@
 #include "libc/assert.h"
 #include "libc/bits/bits.h"
 #include "libc/calls/calls.h"
+#include "libc/calls/sig.internal.h"
 #include "libc/calls/sigbits.h"
+#include "libc/calls/strace.internal.h"
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/stat.h"
 #include "libc/calls/termios.h"
@@ -131,6 +133,9 @@
 #include "libc/errno.h"
 #include "libc/fmt/conv.h"
 #include "libc/intrin/asan.internal.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/intrin/nomultics.internal.h"
+#include "libc/log/check.h"
 #include "libc/log/log.h"
 #include "libc/macros.internal.h"
 #include "libc/mem/mem.h"
@@ -160,6 +165,8 @@ Copyright 2018-2020 Justine Tunney <jtunney@gmail.com>\\n\
 Copyright 2010-2016 Salvatore Sanfilippo <antirez@gmail.com>\\n\
 Copyright 2010-2013 Pieter Noordhuis <pcnoordhuis@gmail.com>\"");
 
+#define LINENOISE_POLL_MS __SIG_POLLING_INTERVAL_MS
+
 #define LINENOISE_MAX_RING    8
 #define LINENOISE_MAX_DEBUG   16
 #define LINENOISE_MAX_HISTORY 1024
@@ -249,7 +256,6 @@ static char maskmode;
 static char ispaused;
 static char iscapital;
 static int historylen;
-extern bool __replmode;
 static struct linenoiseRing ring;
 static struct sigaction orig_int;
 static struct sigaction orig_quit;
@@ -257,6 +263,7 @@ static struct sigaction orig_cont;
 static struct sigaction orig_winch;
 static struct termios orig_termios;
 static char *history[LINENOISE_MAX_HISTORY];
+static linenoisePollCallback *pollCallback;
 static linenoiseXlatCallback *xlatCallback;
 static linenoiseHintsCallback *hintsCallback;
 static linenoiseFreeHintsCallback *freeHintsCallback;
@@ -703,6 +710,22 @@ static void linenoiseDebug(struct linenoiseState *l, const char *fmt, ...) {
   free(msg);
 }
 
+static int linenoisePoll(struct linenoiseState *l, int fd) {
+  int rc, ms;
+  for (ms = LINENOISE_POLL_MS;;) {
+    if (pollCallback) {
+      rc = pollCallback(fd, ms);
+    } else {
+      rc = poll((struct pollfd[]){{fd, POLLIN}}, 1, ms);
+    }
+    if (rc) {
+      return rc;
+    } else {
+      linenoiseRefreshLine(l);
+    }
+  }
+}
+
 static ssize_t linenoiseRead(int fd, char *buf, size_t size,
                              struct linenoiseState *l) {
   ssize_t rc;
@@ -719,6 +742,7 @@ static ssize_t linenoiseRead(int fd, char *buf, size_t size,
     }
     if (l && gotwinch) refreshme = 1;
     if (refreshme) linenoiseRefreshLine(l);
+    if (linenoisePoll(l, fd) == -1) return -1;
     rc = readansi(fd, buf, size);
   } while (rc == -1 && errno == EINTR);
   if (l && rc > 0) {
@@ -777,7 +801,7 @@ void linenoiseClearScreen(int fd) {
 }
 
 static void linenoiseBeep(void) {
-  /* THE TERMINAL BELL IS DEAD - HISTORY HAS KILLED IT */
+  // THE TERMINAL BELL IS DEAD - HISTORY HAS KILLED IT
 }
 
 static char linenoiseGrow(struct linenoiseState *ls, size_t n) {
@@ -829,27 +853,31 @@ static ssize_t linenoiseCompleteLine(struct linenoiseState *ls, char *seq,
     // if there's a multiline completions, then do nothing and wait and
     // see if the user presses tab again. if the user does this we then
     // print ALL the completions, to above the editing line
-    nread = linenoiseRead(ls->ifd, seq, size, ls);
-    if (nread == 1 && seq[0] == '\t') {
-      itemlen = linenoiseMaxCompletionLength(&lc) + 4;
-      perline = MAX(1, (ls->ws.ws_col - 1) / itemlen);
-      abInit(&ab);
-      abAppends(&ab, "\r\033[K");
-      for (i = 0; i < lc.len;) {
-        for (j = 0; i < lc.len && j < perline; ++j, ++i) {
-          n = GetMonospaceWidth(lc.cvec[i], strlen(lc.cvec[i]), 0);
-          abAppends(&ab, lc.cvec[i]);
-          for (k = n; k < itemlen; ++k) {
-            abAppendw(&ab, ' ');
+    for (;;) {
+      nread = linenoiseRead(ls->ifd, seq, size, ls);
+      if (nread == 1 && seq[0] == '\t') {
+        itemlen = linenoiseMaxCompletionLength(&lc) + 4;
+        perline = MAX(1, (ls->ws.ws_col - 1) / itemlen);
+        abInit(&ab);
+        abAppends(&ab, "\r\n\033[K");
+        for (i = 0; i < lc.len;) {
+          for (j = 0; i < lc.len && j < perline; ++j, ++i) {
+            n = GetMonospaceWidth(lc.cvec[i], strlen(lc.cvec[i]), 0);
+            abAppends(&ab, lc.cvec[i]);
+            for (k = n; k < itemlen; ++k) {
+              abAppendw(&ab, ' ');
+            }
           }
+          abAppendw(&ab, READ16LE("\r\n"));
         }
-        abAppendw(&ab, READ16LE("\r\n"));
+        ab.len -= 2;
+        abAppends(&ab, "\n");
+        linenoiseWriteStr(ls->ofd, ab.b);
+        linenoiseRefreshLine(ls);
+        abFree(&ab);
+      } else {
+        break;
       }
-      ab.len -= 2;
-      abAppends(&ab, "\n");
-      linenoiseWriteStr(ls->ofd, ab.b);
-      linenoiseRefreshLine(ls);
-      abFree(&ab);
     }
   }
   linenoiseFreeCompletions(&lc);
@@ -1697,6 +1725,7 @@ static void linenoiseEditCtrlq(struct linenoiseState *l) {
  */
 static ssize_t linenoiseEdit(int stdin_fd, int stdout_fd, const char *prompt,
                              char **obuf) {
+  int st;
   ssize_t rc;
   uint64_t w;
   size_t nread;
@@ -2108,6 +2137,7 @@ char *linenoise(const char *prompt) {
  *     however if it contains a slash / dot then we'll assume prog is
  *     the history filename which as determined by the caller
  * @return chomped allocated string of read line or null on eof/error
+ *     noting that on eof your errno is not changed
  */
 char *linenoiseWithHistory(const char *prompt, const char *prog) {
   char *line, *res;
@@ -2137,7 +2167,9 @@ char *linenoiseWithHistory(const char *prompt, const char *prog) {
     }
   }
   if (path.len) {
-    linenoiseHistoryLoad(path.b);
+    if (linenoiseHistoryLoad(path.b) == -1) {
+      kprintf("%r%s: failed to load history: %m%n", path);
+    }
   }
   line = linenoise(prompt);
   if (path.len && line && *line) {
@@ -2185,6 +2217,13 @@ void linenoiseSetXlatCallback(linenoiseXlatCallback *fn) {
   xlatCallback = fn;
 }
 
+/**
+ * Sets terminal fd pollin callback.
+ */
+void linenoiseSetPollCallback(linenoisePollCallback *fn) {
+  pollCallback = fn;
+}
+
 /**
  * Adds completion.
  *

third_party/linenoise/linenoise.h

@@ -13,12 +13,14 @@ typedef char *(linenoiseHintsCallback)(const char *, const char **,
                                        const char **);
 typedef void(linenoiseFreeHintsCallback)(void *);
 typedef wint_t(linenoiseXlatCallback)(wint_t);
+typedef int(linenoisePollCallback)(int, int);
 
 void linenoiseSetCompletionCallback(linenoiseCompletionCallback *);
 void linenoiseSetHintsCallback(linenoiseHintsCallback *);
 void linenoiseSetFreeHintsCallback(linenoiseFreeHintsCallback *);
 void linenoiseAddCompletion(linenoiseCompletions *, const char *);
 void linenoiseSetXlatCallback(linenoiseXlatCallback *);
+void linenoiseSetPollCallback(linenoisePollCallback *);
 
 char *linenoise(const char *) dontdiscard;
 char *linenoiseRaw(const char *, int, int) dontdiscard;