feat: add printErr, streq and onUsr1

user/hcat.c

@@ -0,0 +1,57 @@
+#include "ulib.h"
+
+/*
+ * Left half of shell.c's new `cmd1 <<< TEXT | cmd2` here-string-into-
+ * pipeline live demo -- jobctl.c's new jobctlSpawnPipedHereString wires
+ * THIS process's fd 0 to a real pipe the shell itself writes the typed
+ * `<<<` text into, AND its fd 1 to the pipeline's shared pipe (right
+ * half's fd 0), both BEFORE this process ever runs a single instruction.
+ * From this program's own point of view there is nothing special about
+ * either fd: it is simply "cat" -- read stdin to real EOF, then write
+ * exactly those bytes to stdout -- with no idea either end is a pipe
+ * rather than a real file or console. Named "hcat" (not "cat") purely so
+ * the driver thread's typed line (binary name + `<<<` + text + `|` +
+ * binary name) stays clearly under keyboard.c's 32-byte
+ * consoleReaderBufferSize per line -- see kmain.c's FALA 31 lesson,
+ * documented right where stderrDriverThread's own path length once
+ * crossed that exact boundary.
+ *
+ * Diagnostics go to fd 2 (never fd 1) for the same reason pipesrc.c's own
+ * printErr does: fd 1 here is the real pipeline payload hsink.c compares
+ * byte-for-byte, and print()/printDec() (ulib.h) are both hardcoded to
+ * fd 1.
+ */
+
+static void printErr(const char* text)
+{
+    userWrite(2, text, stringLength(text));
+}
+
+int main(void)
+{
+    printErr("hcat: reading here-string stdin\n");
+
+    char buffer[64];
+    unsigned long total = 0;
+    for (;;) {
+        long got = userRead(0, buffer + total, sizeof(buffer) - 1 - total);
+        if (got < 0) {
+            printErr("hcat: FAIL read\n");
+            return 1;
+        }
+        if (got == 0)
+            break;
+        total += (unsigned long)got;
+        if (total >= sizeof(buffer) - 1)
+            break;
+    }
+
+    long written = userWrite(1, buffer, total);
+    if (written != (long)total) {
+        printErr("hcat: FAIL short/failed write\n");
+        return 1;
+    }
+
+    printErr("hcat: forwarded payload\n");
+    return 0;
+}

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;
+}

user/jobctlbg.c

@@ -0,0 +1,80 @@
+#include "ulib.h"
+
+/*
+ * Companion to jobctlfg.c: loaded the same way, on demand, when kmain.c's
+ * jobctlDriverThread types "jobctlbg &" at the real interactive shell.
+ * The trailing "&" (shell.c's runProgram) routes this through
+ * jobctlRunBackground (jobctl.c) instead of jobctlSpawnForeground -- own
+ * new process group leader exactly like jobctlfg.c, but the shell never
+ * calls keyboardSetForegroundPgid for it and never blocks waiting for it
+ * either, a real shell's `&` job semantics. This is the CONTROL side of
+ * the jobctlfg/jobctlbg pair: jobctlfg proves the shell's foreground
+ * grant actually reaches an injected Ctrl-C; this file proves that exact
+ * same event does NOT reach a job the shell deliberately left in the
+ * background -- if shell.c's `&` handling or jobctl.c's group-leader
+ * assignment were ever broken such that this process shared jobctlfg's
+ * group (or somehow ended up foreground itself), this process would
+ * already be Dead by the time jobctlDriverThread later tries to prove it
+ * alive, and its own needles below would simply never appear.
+ *
+ * Also exercises the actual sysGetpgid syscall boundary (unreachable from
+ * KTEST, which runs before schedStart() with no int 0x80 path at all) to
+ * confirm jobctl.c's threadSetPgid(pid, pid) call genuinely took effect
+ * from ring3's own point of view, not just internally.
+ */
+
+static volatile int handlerFired = 0;
+
+static void onUsr1(int signum)
+{
+    (void)signum;
+    handlerFired = 1;
+    print("jobctlbg: still-alive-after-ctrlc-ok\n");
+}
+
+int main(void)
+{
+    long myPid = userGetpid();
+    print("jobctlbg: start, pid=");
+    printDec(myPid);
+    print("\n");
+
+    long pgid = userGetpgid(0);
+    if (pgid != myPid) {
+        print("jobctlbg: FAIL expected to be its own group leader\n");
+        return 1;
+    }
+    print("jobctlbg: own-process-group-ok\n");
+
+    if (userSigAction(sigUsr1, onUsr1, 0, 0) == (long)sigSetFailed) {
+        print("jobctlbg: FAIL install handler\n");
+        return 1;
+    }
+
+    long victimHandle = userPipeCreate();
+    if (victimHandle < 0) {
+        print("jobctlbg: FAIL create victim pipe\n");
+        return 1;
+    }
+    long victimFd = userPipeAttach(victimHandle, 0);
+    if (victimFd < 0) {
+        print("jobctlbg: FAIL attach victim pipe\n");
+        return 1;
+    }
+
+    print("jobctlbg: ready, blocking on go pipe\n");
+    char buffer[4];
+    userRead((int)victimFd, buffer, sizeof(buffer));
+
+    if (!handlerFired) {
+        print("jobctlbg: FAIL read returned without being signaled\n");
+        return 1;
+    }
+
+    /* Reached only if the read was genuinely interrupted (errInterrupted,
+       no sigFlagRestart) by onUsr1 above, sent by kmain.c's own driver
+       thread well AFTER the Ctrl-C injected for jobctlfg -- proving this
+       backgrounded process was never touched by it. */
+    print("jobctlbg: resumed-after-signal-ok\n");
+    return 0;
+}