feat: add printErr, streq and onUsr1

user/hsink.c

@@ -0,0 +1,55 @@
+#include "ulib.h"
+
+/*
+ * Right half of shell.c's new `cmd1 <<< TEXT | cmd2` here-string-into-
+ * pipeline live demo -- see hcat.c's own header comment for the full
+ * picture. jobctlSpawnPiped bakes the pipeline's shared pipe's read end
+ * into this process's own fd 0 exactly like pipesink.c's, so the blocking
+ * userRead below has to genuinely retry across timer ticks until hcat.c's
+ * own forwarded write actually lands. Compares the received bytes
+ * byte-for-byte against the exact text kmain.c's driver thread types after
+ * `<<<` plus the single trailing newline jobctlSpawnPipedHereString always
+ * appends (matching a real shell's own `<<<` behavior) -- unlike hcat.c,
+ * this process's own fd 1 (stdout) is NOT part of the pipeline, so
+ * print()/printDec() (ulib.h) reach the real console exactly like
+ * pipesink.c's own needle.
+ */
+#define hsinkPayload "hpipe-ok\n"
+
+static int streq(const char* a, const char* b)
+{
+    while (*a && *a == *b) {
+        a++;
+        b++;
+    }
+    return *a == *b;
+}
+
+int main(void)
+{
+    print("hsink: blocking on read, waiting for hcat\n");
+
+    char buffer[32];
+    unsigned long total = 0;
+    for (;;) {
+        long got = userRead(0, buffer + total, sizeof(buffer) - 1 - total);
+        if (got < 0) {
+            print("hsink: FAIL read\n");
+            return 1;
+        }
+        if (got == 0)
+            break;
+        total += (unsigned long)got;
+        if (total >= sizeof(buffer) - 1)
+            break;
+    }
+    buffer[total] = 0;
+
+    print("hsink: got: ");
+    print(buffer);
+
+    int ok = streq(buffer, hsinkPayload);
+    print(ok ? "hsink: payload-ok\n" : "hsink: payload-FAIL\n");
+
+    return ok ? 0 : 1;
+}