From 44d29a33df81ac07163d5146a9e43a0c4fb80af0 Mon Sep 17 00:00:00 2001
From: Benji Dial <benji6283@gmail.com>
Date: Sun, 13 Sep 2020 22:06:40 -0400
Subject: new shell

---
 src/user/highway/line.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 src/user/highway/line.c

(limited to 'src/user/highway/line.c')

diff --git a/src/user/highway/line.c b/src/user/highway/line.c
new file mode 100644
index 0000000..ca38c9b
--- /dev/null
+++ b/src/user/highway/line.c
@@ -0,0 +1,100 @@
+#include <knob/block.h>
+#include <knob/quit.h>
+#include <knob/task.h>
+#include <knob/user.h>
+#include "cmds.h"
+#include "vars.h"
+
+#define LINE_SIZE 4096
+static char line[LINE_SIZE];
+
+static void line_replace(const char *from) {
+  const char *fi = from;
+  char *ti = line;
+  while (*fi) {
+    if (ti == line + LINE_SIZE) {
+      tell_user_sz("Line too long.\n");
+      line[0] = '\0';
+      return;
+    }
+    if (*fi != '$') {
+      *ti = *fi;
+      ++ti;
+      ++fi;
+      continue;
+    }
+    const char *var_start = ++fi;
+    const char *var_end = var_start;
+    while (*var_end != '$')
+      if (!*var_end++) {
+        tell_user_sz("Unterminated variable name.\n");
+        line[0] = '\0';
+        return;
+      }
+    if (ti + (var_end - var_start) >= line + LINE_SIZE) {
+      tell_user_sz("Line too long.\n");
+      line[0] = '\0';
+      return;
+    }
+    struct no_null_sn vname = {
+      .data = var_start,
+      .length = var_end - var_start
+    };
+    const struct no_null_sn *vval = get_var(vname);
+    if (!vval)
+      vval = &vname;
+    blockcpy(ti, vval->data, vval->length);
+    ti += vval->length;
+    fi = var_end + 1;
+  }
+  *ti = '\0';
+}
+
+void run_line(const char *original_line) {
+  line_replace(original_line);
+  if (!*line)
+    return;
+  const char *space;
+  for (space = line; *space && (*space != ' '); ++space)
+    ;
+  if (blockequ(line, "source", space - line))
+    source(space + 1);
+  else if (blockequ(line, "set", space - line))
+    set(space + 1);
+  else if (blockequ(line, "echo", space - line)) {
+    tell_user_sz(space + 1);
+    tell_user_sz("\n");
+  }
+  else if (blockequ(line, "vars", space - line))
+    dump_vars();
+  else if (blockequ(line, "quit", space - line))
+    quit(space + 1);
+  else if (blockequ(line, "help", space - line))
+    tell_user_sz("Highway is a command shell for Portland OS. It includes variables and a couple\n"
+                 "of pseudo-commands. Variables are addressed by surrounding with \"$\". The\n"
+                 "following list shows each of the pseudo-commands.\n\n"
+                 "  source FILE       run each command in FILE\n"
+                 "  set VAR VALUE     set $VAR$ to VALUE\n"
+                 "  echo STRING       print STRING\n"
+                 "  vars              dump variables\n"
+                 "  quit              exit highway\n"
+                 "  help              show this\n\n");
+  else if (!try_run_command_blocking(line)) {
+    struct no_null_sn arg = {
+      .data = "_path",
+      .length = 5
+    };
+    const struct no_null_sn *path = get_var(arg);
+    if (!path->length) {
+      tell_user_sz("Could not run command.\n");
+      return;
+    }
+    for (uint16_t to_i = LINE_SIZE - 1; to_i >= path->length; --to_i)
+      line[to_i] = line[to_i - path->length];
+    blockcpy(line, path->data, path->length);
+    if (!try_run_command_blocking(line)) {
+      tell_user_sz("Could not run command.\n");
+      return;
+    }
+  }
+}
\ No newline at end of file
-- 
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