Add mdview markdown viewer, reorganize tests/examples and libc layout

- Split tests/ (libc feature tests) and examples/ (real apps); shared app.mk in repo root, was examples/example.mk - libc/io/* split into libc/{conio,env,errno,file,mouse,string,sys, time,video}/ — clearer module boundaries - New examples/mdview/: markdown viewer (Phases 1-5 + light nested lists). Headers (H1-H4), HR, ulist/olist/quote with nesting via leading spaces, fenced code blocks, inline emphasis (bold/italic/ underscore/code), wrap/unwrap mode with soft wrap (F2), horizontal pan (← →) with '>' truncation indicator - libc additions: scroll() in conio (ESTEX SCROLL), strlwr/strupr, gets() test - Makefile updates across tests/ for the new shared app.mk path Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-06-04 22:23:36 +03:00
parent b851e22fa6
commit 737c974400
104 changed files with 2485 additions and 223 deletions
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/*
+ * Exercises lseek() with offsets that span the 16-bit boundary.
+ * big.txt is 102400 bytes (100 KB); every 256-byte block opens with a
+ * "[off=NNNNNNN] block #BBBB " label, so any seek aligned to 256 lands
+ * on a self-identifying marker.
+ */
+
+static void show_marker(int fd, long off)
+{
+    long pos = lseek(fd, off, SEEK_SET);
+    printf("\nseek %ld -> pos=%ld\n", off, pos);
+
+    char buf[28];
+    int n = read(fd, buf, 27);
+    if (n <= 0) {
+        printf("  read failed: %d\n", n);
+        return;
+    }
+    buf[n] = 0;
+    printf("  bytes: \"%s\"\n", buf);
+}
+
+int main(void)
+{
+    int fd = open("BIG.TXT", O_RDONLY);
+    if (fd < 0) {
+        printf("open failed: %d\n", fd);
+        (void)getchar();
+        return 1;
+    }
+
+    /* Total file size. */
+    long size = lseek(fd, 0L, SEEK_END);
+    printf("file size = %ld bytes\n", size);
+
+    /* Seek inside the first 64 KB (high16 = 0). */
+    show_marker(fd, 0L);
+    show_marker(fd, 256L);
+    show_marker(fd, 32768L);
+
+    /* Right at the 64 KB boundary (offset 0x00010000, high16 = 1). */
+    show_marker(fd, 65536L);
+
+    /* Past 64 KB (high16 still 1, low16 != 0). */
+    show_marker(fd, 65536L + 256L);
+    show_marker(fd, 81920L);
+
+    /* Near end of file (size = 102400 = 0x19000, high16 = 1). */
+    show_marker(fd, 102400L - 256L);
+
+    /* SEEK_CUR: from current position, +256. After the previous SEEK_SET
+     * to 102144, then read of 27 bytes, pos is 102171. +256 -> 102427,
+     * which is past EOF — ESTEX should clamp or error. */
+    long after_cur = lseek(fd, 256L, SEEK_CUR);
+    printf("\nSEEK_CUR +256 -> pos=%ld (past EOF)\n", after_cur);
+
+    close(fd);
+    puts("");
+    puts("Press any key to exit...");
+    (void)getchar();
+    return 0;
+}