vms-0d75: Ctrl/T reflexive status line (real handler over the SET CONTROL=T flag)

src/vmsdcl/dcl_cmd_set.c

@@ -764,7 +764,12 @@ static int cmd_set_control(struct dcl_command *cmd)
         if (strcasecmp(tok, "Y") == 0) {
             ctx->ctrl_y_enabled = enable;
         }
-        /* T = Ctrl-T (broadcast) — track but not implemented beyond flag */
+        /* T = Ctrl-T reflexive status line. The DCL input layer's Ctrl-T
+         * (0x14) handler (dcl_main.c) gates the reflexive one-liner on this
+         * flag; SET NOCONTROL=T disables it. Default off (VMS convention). */
+        else if (strcasecmp(tok, "T") == 0) {
+            ctx->ctrl_t_enabled = enable;
+        }
         tok = strtok_r(NULL, ",", &saveptr);
     }
 

src/vmsdcl/dcl_main.c

@@ -278,6 +278,79 @@ static void ctrl_c_handler(int sig)
     }
 }
 
+/*
+ * dcl_emit_ctrl_t_status - the reflexive Ctrl/T handler.
+ *
+ * VMS prints a one-line process status when the user presses Ctrl/T, if
+ * Ctrl/T is enabled (SET CONTROL=T; disabled by default). This is the
+ * handler the input layer invokes on a Ctrl/T (0x14) keystroke.
+ *
+ * The whole line is sourced from the executive's $GETJPI row --
+ * vms_kif_getjpi_self(), the SAME reader SHOW PROCESS uses -- and rendered
+ * by dcl_format_ctrl_t_status() (dcl_terminal.c), which fabricates nothing:
+ * see its citation and per-field sourcing. If the executive is absent (no
+ * /dev/vms) $GETJPI fails and we emit NOTHING rather than a faked line
+ * (INV-6 / CLAUDE.md Rule 9).
+ *
+ * DEFERRED GAP (vms-0d75 follow-up): the image-name field is empty because
+ * OVMX does not yet source JPI$_IMAGNAME for a running image, and the "IO="
+ * token is omitted because JPI$_DIRIO/BUFIO carry no faithful OVMX source
+ * (their fields_valid bits are never set). Both are honest omissions, not
+ * fabrications; filed as a follow-up rather than filled with plausible
+ * numbers.
+ *
+ * Returns 1 if a status line was emitted, 0 otherwise (disabled or no
+ * executive) so the caller knows whether the display needs a refresh.
+ */
+static int dcl_emit_ctrl_t_status(void)
+{
+    struct dcl_context *ctx = dcl_get_context();
+    if (!ctx->ctrl_t_enabled)
+        return 0;   /* SET NOCONTROL=T (VMS default): Ctrl/T is inert */
+
+    struct vms_procinfo info;
+    memset(&info, 0, sizeof(info));
+    if (!(vms_kif_getjpi_self(&info) & 1))
+        return 0;   /* no executive -> no line, never a fabricated one */
+
+    char node[64];
+    ovmx_node_name(node, sizeof(node));
+
+    char line[256];
+    /* No image name: none is activated at the DCL prompt (see the gap note
+     * above). JPI$_IMAGNAME would be sourced here once OVMX tracks it. */
+    if (dcl_format_ctrl_t_status(&info, node, "", time(NULL),
+                                 line, sizeof(line)) & 1) {
+        fputs("\r\n", stdout);
+        fputs(line, stdout);
+        fputs("\r\n", stdout);
+        fflush(stdout);
+        return 1;
+    }
+    return 0;
+}
+
+#ifdef HAVE_READLINE
+/*
+ * Readline binding for Ctrl/T (0x14). Readline's emacs default maps 0x14 to
+ * transpose-chars; this rebind gives it VMS Ctrl/T semantics instead. The
+ * status line is emitted between the current input line and a fresh redraw
+ * of it, so the reflexive line "momentarily interrupts" without disturbing
+ * what the user has typed (OpenVMS User's Manual). When Ctrl/T is disabled
+ * the keystroke is simply swallowed.
+ */
+static int dcl_ctrl_t_rl_handler(int count, int key)
+{
+    (void)count;
+    (void)key;
+    if (dcl_emit_ctrl_t_status()) {
+        rl_on_new_line();
+        rl_forced_update_display();
+    }
+    return 0;
+}
+#endif
+
 /*
  * Terminal configuration for VMS signal/EOF model.
  * - VEOF = 26 (Ctrl+Z is EOF, not Ctrl+D)
@@ -594,6 +667,9 @@ int main(int argc, char *argv[])
         using_history();
         /* Bind Ctrl-B to previous-history (VMS-style recall key) */
         rl_bind_key(2, rl_get_previous_history);
+        /* Bind Ctrl-T (0x14) to the reflexive status-line handler, replacing
+         * readline's default transpose-chars. Gated on SET CONTROL=T. */
+        rl_bind_key(20, dcl_ctrl_t_rl_handler);
 #endif
     }
 

src/vmsdcl/dcl_terminal.c

@@ -17,8 +17,14 @@
 #include <errno.h>
 #include <termios.h>
 #include <ctype.h>
+#include <time.h>
+#include <inttypes.h>
 
 #include "dcl/terminal.h"
+#include "ssdef.h"
+/* struct vms_procinfo + VMS_PI_V_* valid-bit mask (the executive's $GETJPI
+ * contract) -- src/libvmssys/vms_kif.h pulls src/kernel/vms_ioctl.h. */
+#include "vms_kif.h"
 
 /* Path to the shared terminal device table */
 #include "ovmx_layout.h"
@@ -258,3 +264,117 @@ void vms_term_deallocate(const char *device_name)
     fclose(fp);
 }
 
+/*
+ * dcl_format_ctrl_t_status - render the reflexive Ctrl/T status line.
+ *
+ * FORMAT (CLEAN-ROOM, Rule 8). The one-line layout and every field are from
+ * PUBLIC OpenVMS documentation -- the OpenVMS User's Manual, "Interrupting
+ * Command Execution" / "Ctrl/T", which documents:
+ *
+ *     GREEN::MCCARTHY  13:45:02 EVE    CPU=00:00:03.33 PF=778 IO=295 MEM=315
+ *
+ * and defines the fields as: node and user name; current time of day; the
+ * name of the image (program) executing; charged CPU time in
+ * hours:minutes:seconds.hundredths; the accumulated page-fault count; the
+ * level of I/O activity; and memory usage listed in CPU-specific pages.
+ * (No VSI/HPE binary was disassembled; format taken from the manual text.)
+ *
+ * DATA SOURCE (INV-6 / Rule 9 / Rule 11). Every measured field is READ from
+ * the executive's $GETJPI row (struct vms_procinfo) the caller already
+ * fetched with vms_kif_getjpi_self() -- the SAME source SHOW PROCESS reads
+ * (src/vmsdcl/dcl_cmd_show.c). This function fabricates NOTHING: a field
+ * whose fields_valid bit is CLEAR is OMITTED, never printed as a plausible
+ * zero.
+ *
+ *   node   caller-supplied (ovmx_node_name() -> SCSNODE, the VMS node
+ *          identity, NOT the Linux hostname -- INV-4).
+ *   user   info->username (executive-stamped identity, "" if none).
+ *   time   now, formatted as local HH:MM:SS.
+ *   image  caller-supplied JPI$_IMAGNAME. At the DCL prompt no image is
+ *          activated, so this is empty and the field collapses -- which is
+ *          what VMS shows there (the field names the executing image, and
+ *          none is). OVMX does not yet source JPI$_IMAGNAME while an image
+ *          runs; see the gap note in dcl_main.c's Ctrl-T handler.
+ *   CPU    info->cputim (JPI$_CPUTIM, 10ms units) if VMS_PI_V_CPUTIM.
+ *   PF     info->pageflts (JPI$_PAGEFLTS) if VMS_PI_V_PAGEFLTS.
+ *   IO     JPI$_DIRIO+JPI$_BUFIO. OVMX's executive carries these
+ *          STRUCTURAL, valid bit CLEAR (no faithful direct/buffered I/O
+ *          split exists -- src/kernel/vms_ioctl.h), so the field is OMITTED
+ *          rather than fabricated (INV-6). Sourcing it is deferred work.
+ *   MEM    info->pages (JPI$_PPGCNT, resident pages) if VMS_PI_V_PAGES.
+ *
+ * Returns SS$_NORMAL on success, SS$_BADPARAM on a bad argument. The line is
+ * written WITHOUT a trailing newline; the caller frames it.
+ */
+uint32_t dcl_format_ctrl_t_status(const struct vms_procinfo *info,
+                                  const char *node,
+                                  const char *image,
+                                  time_t now,
+                                  char *out, size_t outlen)
+{
+    if (!info || !out || outlen == 0)
+        return SS$_BADPARAM;
+
+    const char *nodestr = (node && node[0]) ? node : "";
+    const char *userstr = info->username;   /* executive identity; may be "" */
+
+    struct tm tmv;
+    localtime_r(&now, &tmv);
+
+    /* Leading identity + time + (optional) image, VMS spacing. */
+    int n = snprintf(out, outlen, "%s::%s   %02d:%02d:%02d   ",
+                     nodestr, userstr,
+                     tmv.tm_hour, tmv.tm_min, tmv.tm_sec);
+    if (n < 0 || (size_t)n >= outlen)
+        return SS$_BADPARAM;
+    size_t len = (size_t)n;
+
+    if (image && image[0]) {
+        n = snprintf(out + len, outlen - len, "%s   ", image);
+        if (n < 0 || (size_t)n >= outlen - len)
+            return SS$_BADPARAM;
+        len += (size_t)n;
+    }
+
+    /* CPU=hh:mm:ss.cc -- JPI$_CPUTIM is in 10ms units (centiseconds). */
+    if (info->fields_valid & VMS_PI_V_CPUTIM) {
+        unsigned long cs = info->cputim;
+        unsigned long total_sec = cs / 100UL;
+        unsigned long cc = cs % 100UL;
+        unsigned long hh = total_sec / 3600UL;
+        unsigned long mm = (total_sec % 3600UL) / 60UL;
+        unsigned long ss = total_sec % 60UL;
+        n = snprintf(out + len, outlen - len,
+                     "CPU=%02lu:%02lu:%02lu.%02lu", hh, mm, ss, cc);
+        if (n < 0 || (size_t)n >= outlen - len)
+            return SS$_BADPARAM;
+        len += (size_t)n;
+    }
+
+    if (info->fields_valid & VMS_PI_V_PAGEFLTS) {
+        n = snprintf(out + len, outlen - len, " PF=%" PRIu32, info->pageflts);
+        if (n < 0 || (size_t)n >= outlen - len)
+            return SS$_BADPARAM;
+        len += (size_t)n;
+    }
+
+    /* IO deliberately omitted: JPI$_DIRIO/BUFIO are unsourced in OVMX
+     * (valid bit never set). Never fabricate it (INV-6). */
+    if (info->fields_valid & (VMS_PI_V_DIRIO | VMS_PI_V_BUFIO)) {
+        n = snprintf(out + len, outlen - len, " IO=%" PRIu32,
+                     info->dirio + info->bufio);
+        if (n < 0 || (size_t)n >= outlen - len)
+            return SS$_BADPARAM;
+        len += (size_t)n;
+    }
+
+    if (info->fields_valid & VMS_PI_V_PAGES) {
+        n = snprintf(out + len, outlen - len, " MEM=%" PRIu32, info->pages);
+        if (n < 0 || (size_t)n >= outlen - len)
+            return SS$_BADPARAM;
+        len += (size_t)n;
+    }
+
+    return SS$_NORMAL;
+}
+

src/vmsdcl/include/dcl/context.h

@@ -76,6 +76,11 @@ struct dcl_context {
     int ctrl_y_enabled;
     pid_t interrupted_pid;    /* PID of Ctrl-Y stopped child (0 = none) */
 
+    /* Control-T handling (SET CONTROL=T / SET NOCONTROL=T). VMS default is
+     * DISABLED (OpenVMS User's Manual, "Interrupting Command Execution":
+     * "Ctrl/T is disabled by default"), so 0 == off until SET CONTROL=T. */
+    int ctrl_t_enabled;
+
     /* User info */
     char username[64];
     char process_name[16];

src/vmsdcl/include/dcl/terminal.h

@@ -147,4 +147,22 @@ struct terminal_device {
  */
 void vms_term_deallocate(const char *device_name);
 
+/*
+ * dcl_format_ctrl_t_status - render the reflexive Ctrl/T status line into
+ * `out` from an executive $GETJPI row. Pure function (no I/O, no executive
+ * call): the caller supplies the vms_procinfo it already read with
+ * vms_kif_getjpi_self(), the VMS node name, the executing image name (""
+ * when none), and the wall-clock time. See the definition in
+ * dcl_terminal.c for the format citation and per-field data sourcing.
+ * Returns SS$_NORMAL on success. `info` is const void* so this header
+ * does not have to pull the kernel ioctl structures.
+ */
+#include <time.h>
+struct vms_procinfo;
+uint32_t dcl_format_ctrl_t_status(const struct vms_procinfo *info,
+                                  const char *node,
+                                  const char *image,
+                                  time_t now,
+                                  char *out, size_t outlen);
+
 #endif /* __DCL_TERMINAL_H */

tests/libvms/CMakeLists.txt

@@ -364,3 +364,26 @@ target_include_directories(test_libvms_conformance_constants PRIVATE
 )
 add_test(NAME test_libvms_conformance_constants
          COMMAND test_libvms_conformance_constants)
+
+# vms-0d75 -- reflexive Ctrl/T status line. Compiles the PRODUCTION renderer
+# (src/vmsdcl/dcl_terminal.c) directly and drives dcl_format_ctrl_t_status()
+# against a struct vms_procinfo -- the executive's real $GETJPI contract --
+# so it proves the format and real-field consumption at the true data
+# boundary, no monkeypatch. dcl_terminal.c needs the DCL, libvms and
+# libvmssys (vms_kif.h -> vms_ioctl.h) include dirs; the vms lib supplies its
+# incidental vms_kif_procscan() reference. _DEFAULT_SOURCE for localtime_r.
+add_executable(test_libvms_ctrl_t_status
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_ctrl_t_status.c
+    ${CMAKE_SOURCE_DIR}/src/vmsdcl/dcl_terminal.c)
+target_include_directories(test_libvms_ctrl_t_status PRIVATE
+    ${CMAKE_SOURCE_DIR}/src/vmsdcl/include
+    ${VMS_INCLUDE_DIR}
+    ${CMAKE_SOURCE_DIR}/src/libvmssys
+)
+target_compile_definitions(test_libvms_ctrl_t_status PRIVATE
+    _POSIX_C_SOURCE=200809L
+    _DEFAULT_SOURCE
+)
+target_link_libraries(test_libvms_ctrl_t_status PRIVATE vms pthread m)
+add_test(NAME test_libvms_ctrl_t_status
+         COMMAND test_libvms_ctrl_t_status)