text: /* getconf.c - get configuration values
   *
   * Copyright 2017 Rob Landley <rob@landley.net>
   *
   * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getconf.c
   *
   * Deviations from posix: no -v because nothing says what it should DO.
   * Added -l, what symbols should be included is a bit unclear.
   * Added -a, copied FSF behavior of assuming "/" if no path supplied.
  
  USE_GETCONF(NEWTOY(getconf, ">2al", TOYFLAG_USR|TOYFLAG_BIN))
  
  config GETCONF
    bool "getconf"
    default y
    help
      usage: getconf -a [PATH] | -l | NAME [PATH]
  
      Get system configuration values. Values from pathconf(3) require a path.
  
      -a	Show all (defaults to "/" if no path given)
      -l	List available value names (grouped by source)
  */
  
  #define FOR_getconf
  #include "toys.h"
  #include <limits.h>
  
  // This is missing on glibc (bionic has it).
  #ifndef _SC_XOPEN_UUCP
  #define _SC_XOPEN_UUCP -1
  #endif
  
  #ifdef __APPLE__
  // macOS doesn't have a bunch of stuff. The actual macOS getconf says
  // "no such parameter", but -- unless proven otherwise -- it seems more useful
  // for portability if we act like we understood but say "undefined"?
  #define _SC_AVPHYS_PAGES -1
  #define _SC_THREAD_ROBUST_PRIO_INHERIT -1
  #define _SC_THREAD_ROBUST_PRIO_PROTECT -1
  #define _SC_UIO_MAXIOV -1
  #define _SC_V7_ILP32_OFF32 -1
  #define _SC_V7_ILP32_OFFBIG -1
  #define _SC_V7_LP64_OFF64 -1
  #define _SC_V7_LPBIG_OFFBIG -1
  #define _CS_V7_ENV -1
  #endif
  
  struct config {
    char *name;
    long long value;
  };
  
  // Lists of symbols getconf can query, broken down by whether we call sysconf(),
  // confstr(), or output the macro value directly.
  
  // Probe the live system
  static struct config sysconfs[] = {
    /* POSIX */
  #define CONF(n) {"_POSIX_" #n,_SC_ ## n}
    CONF(ADVISORY_INFO), CONF(BARRIERS), CONF(ASYNCHRONOUS_IO),
    CONF(CLOCK_SELECTION), CONF(CPUTIME), CONF(FSYNC), CONF(IPV6),
    CONF(JOB_CONTROL), CONF(MAPPED_FILES), CONF(MEMLOCK), CONF(MEMLOCK_RANGE),
    CONF(MEMORY_PROTECTION), CONF(MESSAGE_PASSING), CONF(MONOTONIC_CLOCK),
    CONF(PRIORITY_SCHEDULING), CONF(RAW_SOCKETS), CONF(READER_WRITER_LOCKS),
    CONF(REALTIME_SIGNALS), CONF(REGEXP), CONF(SAVED_IDS), CONF(SEMAPHORES),
    CONF(SHARED_MEMORY_OBJECTS), CONF(SHELL), CONF(SPAWN), CONF(SPIN_LOCKS),
    CONF(SPORADIC_SERVER), CONF(SS_REPL_MAX), CONF(SYNCHRONIZED_IO),
    CONF(THREAD_ATTR_STACKADDR), CONF(THREAD_ATTR_STACKSIZE),
    CONF(THREAD_CPUTIME), CONF(THREAD_PRIO_INHERIT), CONF(THREAD_PRIO_PROTECT),
    CONF(THREAD_PRIORITY_SCHEDULING), CONF(THREAD_PROCESS_SHARED),
    CONF(THREAD_ROBUST_PRIO_INHERIT), CONF(THREAD_ROBUST_PRIO_PROTECT),
    CONF(THREAD_SAFE_FUNCTIONS), CONF(THREAD_SPORADIC_SERVER), CONF(THREADS),
    CONF(TIMEOUTS), CONF(TIMERS), CONF(TRACE), CONF(TRACE_EVENT_FILTER),
    CONF(TRACE_EVENT_NAME_MAX), CONF(TRACE_INHERIT), CONF(TRACE_LOG),
    CONF(TRACE_NAME_MAX), CONF(TRACE_SYS_MAX), CONF(TRACE_USER_EVENT_MAX),
    CONF(TYPED_MEMORY_OBJECTS), CONF(VERSION), CONF(V7_ILP32_OFF32),
    CONF(V7_ILP32_OFFBIG), CONF(V7_LP64_OFF64), CONF(V7_LPBIG_OFFBIG),
  
    /* POSIX.2 */
  #undef CONF
  #define CONF(n) {"POSIX2_" #n,_SC_2_ ## n}
    CONF(C_BIND), CONF(C_DEV), CONF(CHAR_TERM), CONF(FORT_DEV), CONF(FORT_RUN),
    CONF(LOCALEDEF), CONF(PBS), CONF(PBS_ACCOUNTING), CONF(PBS_CHECKPOINT),
    CONF(PBS_LOCATE), CONF(PBS_MESSAGE), CONF(PBS_TRACK), CONF(SW_DEV),
    CONF(UPE), CONF(VERSION),
  
    /* X/Open */
  #undef CONF
  #define CONF(n) {"_XOPEN_" #n,_SC_XOPEN_ ## n}
    CONF(CRYPT), CONF(ENH_I18N), CONF(REALTIME), CONF(REALTIME_THREADS),
    CONF(SHM), CONF(STREAMS), CONF(UNIX), CONF(UUCP), CONF(VERSION),
  
    /* No obvious standard */
  #undef CONF
  #define CONF(n) {#n,_SC_ ## n}
    CONF(AIO_LISTIO_MAX), CONF(AIO_MAX), CONF(AIO_PRIO_DELTA_MAX), CONF(ARG_MAX),
    CONF(ATEXIT_MAX), CONF(BC_BASE_MAX), CONF(BC_DIM_MAX), CONF(BC_SCALE_MAX),
    CONF(BC_STRING_MAX), CONF(CHILD_MAX), CONF(CLK_TCK), CONF(COLL_WEIGHTS_MAX),
    CONF(DELAYTIMER_MAX), CONF(EXPR_NEST_MAX), CONF(HOST_NAME_MAX),
    CONF(IOV_MAX), CONF(LINE_MAX), CONF(LOGIN_NAME_MAX), CONF(NGROUPS_MAX),
    CONF(MQ_OPEN_MAX), CONF(MQ_PRIO_MAX), CONF(OPEN_MAX), CONF(PAGE_SIZE),
    CONF(PAGESIZE), CONF(RAW_SOCKETS), CONF(RE_DUP_MAX), CONF(RTSIG_MAX),
    CONF(SEM_NSEMS_MAX), CONF(SEM_VALUE_MAX), CONF(SIGQUEUE_MAX),
    CONF(STREAM_MAX), CONF(SYMLOOP_MAX), CONF(TIMER_MAX), CONF(TTY_NAME_MAX),
    CONF(TZNAME_MAX), CONF(UIO_MAXIOV),
  
    /* Names that just don't match the symbol, do it by hand */
    {"_AVPHYS_PAGES", _SC_AVPHYS_PAGES}, {"_PHYS_PAGES", _SC_PHYS_PAGES},
    {"_NPROCESSORS_CONF", _SC_NPROCESSORS_CONF},
    {"_NPROCESSORS_ONLN", _SC_NPROCESSORS_ONLN},
  
    /* There's a weird "PTHREAD" vs "THREAD" mismatch here. */
    {"PTHREAD_DESTRUCTOR_ITERATIONS", _SC_THREAD_DESTRUCTOR_ITERATIONS},
    {"PTHREAD_KEYS_MAX", _SC_THREAD_KEYS_MAX},
    {"PTHREAD_STACK_MIN", _SC_THREAD_STACK_MIN},
    {"PTHREAD_THREADS_MAX", _SC_THREAD_THREADS_MAX},
  };
  
  // Probe the live system with a path
  static struct config pathconfs[] = {
  #undef CONF
  #define CONF(n) {#n,_PC_ ## n}
    CONF(ASYNC_IO), CONF(CHOWN_RESTRICTED), CONF(FILESIZEBITS), CONF(LINK_MAX),
    CONF(MAX_CANON), CONF(MAX_INPUT), CONF(NAME_MAX), CONF(NO_TRUNC),
    CONF(PATH_MAX), CONF(PIPE_BUF), CONF(PRIO_IO), CONF(SYMLINK_MAX),
    CONF(SYNC_IO),
    {"_POSIX_VDISABLE", _PC_VDISABLE},
  };
  
  // Strings out of a header
  static struct config confstrs[] = {
  #undef CONF
  #define CONF(n) {#n,_CS_ ## n}
    CONF(PATH), CONF(V7_ENV)
  };
  
  // Integers out of a header
  static struct config limits[] = {
  #undef CONF
  #define CONF(n) {#n,n}
    CONF(_POSIX_AIO_LISTIO_MAX), CONF(_POSIX_AIO_MAX), CONF(_POSIX_ARG_MAX),
    CONF(_POSIX_CHILD_MAX), CONF(_POSIX_DELAYTIMER_MAX),
    CONF(_POSIX_HOST_NAME_MAX), CONF(_POSIX_LINK_MAX),
    CONF(_POSIX_LOGIN_NAME_MAX), CONF(_POSIX_MAX_CANON),
    CONF(_POSIX_MAX_INPUT), CONF(_POSIX_NAME_MAX), CONF(_POSIX_NGROUPS_MAX),
    CONF(_POSIX_OPEN_MAX), CONF(_POSIX_PATH_MAX), CONF(_POSIX_PIPE_BUF),
    CONF(_POSIX_RE_DUP_MAX), CONF(_POSIX_RTSIG_MAX), CONF(_POSIX_SEM_NSEMS_MAX),
    CONF(_POSIX_SEM_VALUE_MAX), CONF(_POSIX_SIGQUEUE_MAX), CONF(_POSIX_SSIZE_MAX),
    CONF(_POSIX_STREAM_MAX), CONF(_POSIX_SYMLINK_MAX), CONF(_POSIX_SYMLOOP_MAX),
    CONF(_POSIX_THREAD_DESTRUCTOR_ITERATIONS), CONF(_POSIX_THREAD_KEYS_MAX),
    CONF(_POSIX_THREAD_THREADS_MAX), CONF(_POSIX_TIMER_MAX),
    CONF(_POSIX_TTY_NAME_MAX), CONF(_POSIX_TZNAME_MAX),
    CONF(CHAR_MAX), CONF(CHAR_MIN), CONF(INT_MAX), CONF(INT_MIN), CONF(SCHAR_MAX),
    CONF(SCHAR_MIN), CONF(SHRT_MAX), CONF(SHRT_MIN), CONF(SSIZE_MAX),
    CONF(UCHAR_MAX), CONF(UINT_MAX), CONF(ULONG_MAX), CONF(USHRT_MAX),
    CONF(CHAR_BIT),
    /* Not available in glibc without _GNU_SOURCE. */
    {"LONG_BIT", 8*sizeof(long)},
    {"WORD_BIT", 8*sizeof(int)},
  #undef CONF
  #define CONF(n) {#n,_ ## n}
    CONF(POSIX2_BC_BASE_MAX), CONF(POSIX2_BC_DIM_MAX),
    CONF(POSIX2_BC_SCALE_MAX), CONF(POSIX2_BC_STRING_MAX),
    CONF(POSIX2_CHARCLASS_NAME_MAX), CONF(POSIX2_COLL_WEIGHTS_MAX),
    CONF(POSIX2_EXPR_NEST_MAX), CONF(POSIX2_LINE_MAX), CONF(POSIX2_RE_DUP_MAX),
  };
  
  // Names we need to handle ourselves (default to blank but shouldn't error)
  static struct config others[] = {
    {"LFS_CFLAGS", 0}, {"LFS_LDFLAGS", 0}, {"LFS_LIBS", 0}
  };
  
  static void show_conf(int i, struct config *c, const char *path)
  {
    if (i<2) {
      long l = i ? pathconf(path, c->value) : sysconf(c->value);
  
      if (l == -1) puts("undefined");
      else printf("%ld\n", l);
    } else if (i==2) {
      confstr(c->value, toybuf, sizeof(toybuf));
      puts(toybuf);
    } else if (i==3) printf("%lld\n", c->value);
    // LFS_CFLAGS on 32 bit should enable Large File Support for kernel builds
    else puts(sizeof(long)==4 && !strcmp(c->name, "LFS_CFLAGS") ?
      "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64" : "");
  }
  
  void getconf_main(void)
  {
    struct config *configs[] = {sysconfs, pathconfs, confstrs, limits, others},
      *c = NULL;
    int i, j, lens[] = {ARRAY_LEN(sysconfs), ARRAY_LEN(pathconfs),
      ARRAY_LEN(confstrs), ARRAY_LEN(limits), ARRAY_LEN(others)};
    char *name, *path = (toys.optc==2) ? toys.optargs[1] : "/",
      *config_names[] = {"sysconf(3)", "pathconf(3)", "confstr(3)",
      "<limits.h>", "Misc"};
  
    if (toys.optflags&FLAG_a) {
      for (i = 0; i<5; i++) {
        for (j = 0; j<lens[i]; j++) {
          c = &configs[i][j];
          printf("%-34s ", c->name);
          show_conf(i, c, path);
        }
      }
      return;
    }
  
    if (toys.optflags&FLAG_l) {
      for (i = 0; i<5; i++) {
        printf("%s\n", config_names[i]);
        for (j = 0; j<lens[i]; j++) printf("  %s\n", configs[i][j].name);
      }
      return;
    }
  
    if (toys.optc<1) help_exit(0);
    name = *toys.optargs;
  
    // Workaround for autogen using CS_PATH instead of PATH
    if (!strcmp("CS_PATH", name)) name += 3;
  
    // Find the config.
    for (i = j = 0; ; j++) {
      if (j==lens[i]) j = 0, i++;
      if (i==5) error_exit("bad '%s'", name);
      c = &configs[i][j];
      if (!strcmp(c->name, name)) break;
    }
  
    // Check that we do/don't have the extra path argument.
    if (i==1) {
      if (toys.optc!=2) help_exit("%s needs a path", name);
    } else if (toys.optc!=1) help_exit("%s does not take a path", name);
  
    show_conf(i, c, path);
  }
  