# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1705601594 -3600
# Node ID b4e5ea9661c6e96b9dcf3f2c8c95dd37cc9192a3
# Parent  e3d2ac731e491fbbd0bc6ad3a74f452d788a030b
Allow programs to be initiated as jobs to be monitored and completed explicitly.

diff -r e3d2ac731e49 -r b4e5ea9661c6 fsaccess/fsaccess.c
--- a/fsaccess/fsaccess.c	Wed Jan 17 18:56:05 2024 +0100
+++ b/fsaccess/fsaccess.c	Thu Jan 18 19:13:14 2024 +0100
@@ -53,13 +53,16 @@
   script        Read operations from a script file (or stdin)\n\
 Execution operations:\n\
 \n\
+  jobs          Show initiated programs\n\
   run           Run a program from the filesystem\n\
+  wait          Wait for a program to finish\n\
 ";
 
 /* Operations exposed by the program. */
 
 struct operation operations[] = {
     {"copy-in", copy_in},
+    {"jobs", show_programs},
     {"ls", list_objects},
     {"mkdir", make_dirs},
     {"rm", remove_non_dirs},
@@ -67,6 +70,7 @@
     {"run", run_program},
     {"script", run_script},
     {"stat", stat_objects},
+    {"wait", wait_program},
     {NULL, NULL},
     };
 
diff -r e3d2ac731e49 -r b4e5ea9661c6 fsaccess/op_run.c
--- a/fsaccess/op_run.c	Wed Jan 17 18:56:05 2024 +0100
+++ b/fsaccess/op_run.c	Thu Jan 18 19:13:14 2024 +0100
@@ -1,5 +1,5 @@
 /*
- * Run a program residing in the filesystem.
+ * Run programs residing in the filesystem.
  *
  * Copyright (C) 2022, 2023, 2024 Paul Boddie <paul@boddie.org.uk>
  *
@@ -27,6 +27,8 @@
 #include <systypes/format.h>
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include "ops.h"
 
@@ -38,15 +40,60 @@
 
 
 
+/* Initiated programs (jobs).
+   NOTE: Arbitrary limit. */
+
+#define NUMBER_OF_JOBS 32
+
+static file_t *readers[NUMBER_OF_JOBS] = {NULL};
+static process_t *processes[NUMBER_OF_JOBS] = {NULL};
+static const char *programs[NUMBER_OF_JOBS] = {NULL};
+static int next_job = 0;
+
+
+
+/* Wait for a program to finish, showing its output. */
+
+static int _wait_program(file_t *reader, process_t *process)
+{
+  char buffer[TO_TRANSFER];
+  notify_flags_t flags;
+  notify_values_t values;
+  long err;
+
+  /* Read until the pipe yields no more data. */
+
+  while (1)
+  {
+    offset_t nread = client_read(reader, buffer, TO_TRANSFER);
+
+    if (nread)
+      fwrite(buffer, sizeof(char), nread, stdout);
+    else
+      break;
+  }
+
+  /* Close the pipe and obtain the process state. */
+
+  client_close(reader);
+
+  err = process_wait(process, &flags, &values);
+
+  printf("End process (flags %" pFMTnotify_flags "x values: %ld, %ld)\n", flags, values.sig, values.val);
+
+  if (err)
+    return -1;
+
+  return values.val;
+}
+
 /* Run the given program. */
 
 int run_program(int argc, char *argv[])
 {
-  char buffer[TO_TRANSFER];
   process_t *process;
   file_t *reader, *writer;
-  notify_flags_t flags;
-  notify_values_t values;
+  int last_job;
   long err;
 
   /* Create a pipe for process output. */
@@ -75,30 +122,71 @@
 
   client_close(writer);
 
-  /* Read until the pipe yields no more data. */
+  /* Record the output stream. */
 
-  while (1)
+  last_job = next_job;
+
+  while (readers[next_job] != NULL)
   {
-    offset_t nread = client_read(reader, buffer, TO_TRANSFER);
+    next_job++;
+
+    if (next_job >= NUMBER_OF_JOBS)
+      next_job = 0;
 
-    if (nread)
-      fwrite(buffer, sizeof(char), nread, stdout);
-    else
-      break;
+    /* Wait for the process to complete if no more job slots are available. */
+
+    if (next_job == last_job)
+      return _wait_program(reader, process);
   }
 
-  /* Close the pipe and obtain the process state. */
+  readers[next_job] = reader;
+  processes[next_job] = process;
+  programs[next_job] = strdup(argv[0]);
+
+  return 0;
+}
 
-  client_close(reader);
+/* Show initiated programs. */
+
+int show_programs(int argc, char *argv[])
+{
+  (void) argc; (void) argv;
+
+  int job_number;
 
-  err = process_wait(process, &flags, &values);
+  for (job_number = 0; job_number < NUMBER_OF_JOBS; job_number++)
+  {
+    if (readers[job_number] != NULL)
+      printf("[%d] %s\n", job_number, programs[job_number]);
+  }
+
+  return 0;
+}
 
-  printf("End process (flags %" pFMTnotify_flags "x values: %ld, %ld)\n", flags, values.sig, values.val);
+/* Wait for the indicated program to finish, showing its output. */
 
-  if (err)
+int wait_program(int argc, char *argv[])
+{
+  int job_number;
+  int exitcode;
+
+  if (argc < 1)
     return -1;
 
-  return values.val;
+  job_number = atoi(argv[0]);
+
+  if (readers[job_number] == NULL)
+    return -1;
+
+  exitcode = _wait_program(readers[job_number], processes[job_number]);
+
+  readers[job_number] = NULL;
+  processes[job_number] = NULL;
+
+  free(programs[job_number]);
+  programs[job_number] = NULL;
+
+  return exitcode;
 }
 
 /* vim: tabstop=2 expandtab shiftwidth=2
diff -r e3d2ac731e49 -r b4e5ea9661c6 fsaccess/ops.h
--- a/fsaccess/ops.h	Wed Jan 17 18:56:05 2024 +0100
+++ b/fsaccess/ops.h	Thu Jan 18 19:13:14 2024 +0100
@@ -52,7 +52,9 @@
 int remove_non_dirs(int argc, char *argv[]);
 int run_program(int argc, char *argv[]);
 int run_script(int argc, char *argv[]);
+int show_programs(int argc, char *argv[]);
 int stat_objects(int argc, char *argv[]);
+int wait_program(int argc, char *argv[]);
 
 /* vim: tabstop=4 expandtab shiftwidth=4
 */