libinput Generic way of gathering user commandline input

libinput/in_input.c

@@ -0,0 +1,125 @@
+#include <in_gb.h>
+#include <kb.h>
+#include <malloc.h>
+#include <minmax.h>
+#include <mprintf.h>
+#include <process_self.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <streams.h>
+#include <string.h>
+#include <system.h>
+#include <tcursor.h>
+#include <tscreen.h>
+
+static void* in_wmalloc (void* ctx, size_t size) {
+  (void)ctx;
+  return malloc (size);
+}
+
+static void in_wfree (void* ctx, void* mem) {
+  (void)ctx;
+  free (mem);
+}
+
+static void* in_wrealloc (void* ctx, void* mem, size_t old, size_t new) {
+  (void)ctx, (void)old;
+  return realloc (mem, new);
+}
+
+struct edit_line {
+  struct in_gb gb;
+  size_t cursor;
+};
+
+void in_stream_read_line (const char* prompt, char* buffer, size_t max) {
+  struct edit_line edit_line;
+  memset (&edit_line, 0, sizeof (edit_line));
+  const char* render = NULL;
+
+  in_gb_init (&in_wmalloc, NULL, &edit_line.gb, max);
+  edit_line.cursor = 0;
+
+  mprintf ("%s", prompt);
+
+  for (;;) {
+    uint8_t ch;
+
+    if (stream_read (process_get_pgid (), STREAM_IN, &ch, 1) <= 0) {
+      sched ();
+      continue;
+    }
+
+    if (ch == '\n')
+      break;
+
+    in_gb_move (&edit_line.gb, edit_line.cursor);
+
+    switch (ch) {
+    case '\b':
+      if (edit_line.cursor > 0) {
+        edit_line.cursor--;
+        in_gb_backspace (&edit_line.gb);
+
+        mprintf (ANSIQ_CUR_LEFT (1));
+
+        char* tail = in_gb_string_at (&in_wmalloc, NULL, &edit_line.gb, edit_line.cursor);
+        mprintf ("%s" ANSIQ_SCR_CLR2LEND, tail);
+
+        int move_back = strlen (tail);
+        if (move_back > 0)
+          mprintf (ANSIQ_DYN_CUR_LEFT, move_back);
+      }
+      break;
+    case KB_DELETE:
+      if (edit_line.cursor < in_gb_length (&edit_line.gb)) {
+        edit_line.gb.gap_end++;
+
+        char* tail = in_gb_string_at (&in_wmalloc, NULL, &edit_line.gb, edit_line.cursor);
+        mprintf ("%s" ANSIQ_SCR_CLR2LEND, tail);
+
+        int move_back = strlen (tail);
+        if (move_back > 0)
+          mprintf (ANSIQ_DYN_CUR_LEFT, move_back);
+      }
+      break;
+    case KB_LEFT:
+      if (edit_line.cursor > 0) {
+        edit_line.cursor--;
+        mprintf (ANSIQ_CUR_LEFT (1));
+      }
+      break;
+    case KB_RIGHT:
+      if (edit_line.cursor < in_gb_length (&edit_line.gb)) {
+        edit_line.cursor++;
+        mprintf (ANSIQ_CUR_RIGHT (1));
+      }
+      break;
+    default:
+      if (isprint (ch)) {
+        in_gb_insert (&in_wrealloc, NULL, &edit_line.gb, ch);
+        edit_line.cursor++;
+
+        if (edit_line.cursor == in_gb_length (&edit_line.gb)) {
+          mprintf ("%c", ch);
+        } else {
+          char* tail = in_gb_string_at (&in_wmalloc, NULL, &edit_line.gb, edit_line.cursor - 1);
+          size_t move_back = strlen (tail) - 1;
+          mprintf ("%s" ANSIQ_DYN_CUR_LEFT, tail, move_back);
+        }
+      }
+      break;
+    }
+  }
+
+  mprintf ("\n");
+
+  render = in_gb_string_at (&in_wmalloc, NULL, &edit_line.gb, 0);
+
+  if (render != NULL) {
+    size_t len_render = strlen (render);
+    memcpy (buffer, render, min (len_render, max));
+  }
+
+  in_gb_fini (&in_wfree, NULL, &edit_line.gb);
+}