feat: add streq and printErr

user/fifomaster.c

@@ -0,0 +1,56 @@
+#include "ulib.h"
+
+/*
+ * Drives the shared-pipe demo added this wave (pipeCreateDetached/
+ * pipeAddReader/pipeAddWriter, pipe.h; vfsPipeCreateHandle/vfsPipeAttach,
+ * vfs.h; sysRead/sysWrite's retry-the-syscall path, syscall.c): creates one
+ * detached pipe handle and hands it to two INDEPENDENTLY spawned processes
+ * as a decimal argv string (decToString/parseDec, ulib.c) rather than a
+ * shared fd -- frostbyte has no fork(), so a raw pipe.h handle number is
+ * the only thing two unrelated processes can rendezvous on. fifowriter.c
+ * deliberately sleeps before writing, so fiforeader.c's read() genuinely
+ * has to block across several timer ticks and be woken later, not just win
+ * a scheduling race against an already-full buffer -- see fifowriter.c/
+ * fiforeader.c for how each end proves that on its own side.
+ */
+
+int main(void)
+{
+    print("fifomaster: start, pid=");
+    printDec(userGetpid());
+    print("\n");
+
+    long handle = userPipeCreate();
+    if (handle < 0) {
+        print("fifomaster: FAIL pipe create\n");
+        return 1;
+    }
+
+    char handleStr[24];
+    decToString(handle, handleStr);
+
+    char* readerArgv[] = { "/bin/fiforeader", handleStr, 0 };
+    long readerPid = userSpawn("/bin/fiforeader", readerArgv);
+    if (readerPid < 0) {
+        print("fifomaster: FAIL spawn fiforeader\n");
+        return 1;
+    }
+
+    char* writerArgv[] = { "/bin/fifowriter", handleStr, 0 };
+    long writerPid = userSpawn("/bin/fifowriter", writerArgv);
+    if (writerPid < 0) {
+        print("fifomaster: FAIL spawn fifowriter\n");
+        return 1;
+    }
+
+    long readerStatus = userWait(readerPid);
+    long writerStatus = userWait(writerPid);
+
+    if (readerStatus != 0 || writerStatus != 0) {
+        print("fifomaster: FAIL reader or writer reported failure\n");
+        return 1;
+    }
+
+    print("fifomaster: pipeshare ok\n");
+    return 0;
+}