ZSYS(3)

NAME
zsys - Class for system-level methods

SYNOPSIS

//  This is a stable class, and may not change except for emergencies. It
//  is provided in stable builds.
//  This class has draft methods, which may change over time. They are not
//  in stable releases, by default. Use --enable-drafts to enable.
// Callback for interrupt signal handler
typedef void (zsys_handler_fn) (
    int signal_value);
//  Initialize CZMQ zsys layer; this happens automatically when you create
//  a socket or an actor; however this call lets you force initialization
//  earlier, so e.g. logging is properly set-up before you start working.
//  Not threadsafe, so call only from main thread. Safe to call multiple
//  times. Returns global CZMQ context.
CZMQ_EXPORT void *
    zsys_init (void);
//  Optionally shut down the CZMQ zsys layer; this normally happens automatically
//  when the process exits; however this call lets you force a shutdown
//  earlier, avoiding any potential problems with atexit() ordering, especially
//  with Windows dlls.
CZMQ_EXPORT void
    zsys_shutdown (void);
//  Get a new ZMQ socket, automagically creating a ZMQ context if this is
//  the first time. Caller is responsible for destroying the ZMQ socket
//  before process exits, to avoid a ZMQ deadlock. Note: you should not use
//  this method in CZMQ apps, use zsock_new() instead.
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT void *
    zsys_socket (int type, const char *filename, size_t line_nbr);
//  Destroy/close a ZMQ socket. You should call this for every socket you
//  create using zsys_socket().
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT int
    zsys_close (void *handle, const char *filename, size_t line_nbr);
//  Return ZMQ socket name for socket type
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT char *
    zsys_sockname (int socktype);
//  Create a pipe, which consists of two PAIR sockets connected over inproc.
//  The pipe is configured to use the zsys_pipehwm setting. Returns the
//  frontend socket successful, NULL if failed.
CZMQ_EXPORT zsock_t *
    zsys_create_pipe (zsock_t **backend_p);
//  Set interrupt handler; this saves the default handlers so that a
//  zsys_handler_reset () can restore them. If you call this multiple times
//  then the last handler will take affect. If handler_fn is NULL, disables
//  default SIGINT/SIGTERM handling in CZMQ.
CZMQ_EXPORT void
    zsys_handler_set (zsys_handler_fn *handler_fn);
//  Reset interrupt handler, call this at exit if needed
CZMQ_EXPORT void
    zsys_handler_reset (void);
//  Set default interrupt handler, so Ctrl-C or SIGTERM will set
//  zsys_interrupted. Idempotent; safe to call multiple times.
//  Can be suppressed by ZSYS_SIGHANDLER=false
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT void
    zsys_catch_interrupts (void);
//  Return 1 if file exists, else zero
CZMQ_EXPORT bool
    zsys_file_exists (const char *filename);
//  Return file modification time. Returns 0 if the file does not exist.
CZMQ_EXPORT time_t
    zsys_file_modified (const char *filename);
//  Return file mode; provides at least support for the POSIX S_ISREG(m)
//  and S_ISDIR(m) macros and the S_IRUSR and S_IWUSR bits, on all boxes.
//  Returns a mode_t cast to int, or -1 in case of error.
CZMQ_EXPORT int
    zsys_file_mode (const char *filename);
//  Delete file. Does not complain if the file is absent
CZMQ_EXPORT int
    zsys_file_delete (const char *filename);
//  Check if file is 'stable'
CZMQ_EXPORT bool
    zsys_file_stable (const char *filename);
//  Create a file path if it doesn't exist. The file path is treated as
//  printf format.
CZMQ_EXPORT int
    zsys_dir_create (const char *pathname, ...);
//  Remove a file path if empty; the pathname is treated as printf format.
CZMQ_EXPORT int
    zsys_dir_delete (const char *pathname, ...);
//  Move to a specified working directory. Returns 0 if OK, -1 if this failed.
CZMQ_EXPORT int
    zsys_dir_change (const char *pathname);
//  Set private file creation mode; all files created from here will be
//  readable/writable by the owner only.
CZMQ_EXPORT void
    zsys_file_mode_private (void);
//  Reset default file creation mode; all files created from here will use
//  process file mode defaults.
CZMQ_EXPORT void
    zsys_file_mode_default (void);
//  Return the CZMQ version for run-time API detection; returns version
//  number into provided fields, providing reference isn't null in each case.
CZMQ_EXPORT void
    zsys_version (int *major, int *minor, int *patch);
//  Format a string using printf formatting, returning a freshly allocated
//  buffer. If there was insufficient memory, returns NULL. Free the returned
//  string using zstr_free().
CZMQ_EXPORT char *
    zsys_sprintf (const char *format, ...);
//  Format a string with a va_list argument, returning a freshly allocated
//  buffer. If there was insufficient memory, returns NULL. Free the returned
//  string using zstr_free().
CZMQ_EXPORT char *
    zsys_vprintf (const char *format, va_list argptr);
//  Create UDP beacon socket; if the routable option is true, uses
//  multicast (not yet implemented), else uses broadcast. This method
//  and related ones might _eventually_ be moved to a zudp class.
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT SOCKET
    zsys_udp_new (bool routable);
//  Close a UDP socket
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT int
    zsys_udp_close (SOCKET handle);
//  Send zframe to UDP socket, return -1 if sending failed due to
//  interface having disappeared (happens easily with WiFi)
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT int
    zsys_udp_send (SOCKET udpsock, zframe_t *frame, inaddr_t *address, int addrlen);
//  Receive zframe from UDP socket, and set address of peer that sent it
//  The peername must be a char [INET_ADDRSTRLEN] array if IPv6 is disabled or
//  NI_MAXHOST if it's enabled. Returns NULL when failing to get peer address.
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT zframe_t *
    zsys_udp_recv (SOCKET udpsock, char *peername, int peerlen);
//  Handle an I/O error on some socket operation; will report and die on
//  fatal errors, and continue silently on "try again" errors.
//  *** This is for CZMQ internal use only and may change arbitrarily ***
CZMQ_EXPORT void
    zsys_socket_error (const char *reason);
//  Return current host name, for use in public tcp:// endpoints. Caller gets
//  a freshly allocated string, should free it using zstr_free(). If the host
//  name is not resolvable, returns NULL.
CZMQ_EXPORT char *
    zsys_hostname (void);
//  Move the current process into the background. The precise effect depends
//  on the operating system. On POSIX boxes, moves to a specified working
//  directory (if specified), closes all file handles, reopens stdin, stdout,
//  and stderr to the null device, and sets the process to ignore SIGHUP. On
//  Windows, does nothing. Returns 0 if OK, -1 if there was an error.
CZMQ_EXPORT int
    zsys_daemonize (const char *workdir);
//  Drop the process ID into the lockfile, with exclusive lock, and switch
//  the process to the specified group and/or user. Any of the arguments
//  may be null, indicating a no-op. Returns 0 on success, -1 on failure.
//  Note if you combine this with zsys_daemonize, run after, not before
//  that method, or the lockfile will hold the wrong process ID.
CZMQ_EXPORT int
    zsys_run_as (const char *lockfile, const char *group, const char *user);
//  Returns true if the underlying libzmq supports CURVE security.
//  Uses a heuristic probe according to the version of libzmq being used.
CZMQ_EXPORT bool
    zsys_has_curve (void);
//  Configure the number of I/O threads that ZeroMQ will use. A good
//  rule of thumb is one thread per gigabit of traffic in or out. The
//  default is 1, sufficient for most applications. If the environment
//  variable ZSYS_IO_THREADS is defined, that provides the default.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_set_io_threads (size_t io_threads);
//  Configure the scheduling policy of the ZMQ context thread pool.
//  Not available on Windows. See the sched_setscheduler man page or sched.h
//  for more information. If the environment variable ZSYS_THREAD_SCHED_POLICY
//  is defined, that provides the default.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_set_thread_sched_policy (int policy);
//  Configure the scheduling priority of the ZMQ context thread pool.
//  Not available on Windows. See the sched_setscheduler man page or sched.h
//  for more information. If the environment variable ZSYS_THREAD_PRIORITY is
//  defined, that provides the default.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_set_thread_priority (int priority);
//  Configure the numeric prefix to each thread created for the internal
//  context's thread pool. This option is only supported on Linux.
//  If the environment variable ZSYS_THREAD_NAME_PREFIX is defined, that
//  provides the default.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_set_thread_name_prefix (int prefix);
//  Return thread name prefix.
CZMQ_EXPORT int
    zsys_thread_name_prefix (void);
//  Adds a specific CPU to the affinity list of the ZMQ context thread pool.
//  This option is only supported on Linux.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_thread_affinity_cpu_add (int cpu);
//  Removes a specific CPU to the affinity list of the ZMQ context thread pool.
//  This option is only supported on Linux.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_thread_affinity_cpu_remove (int cpu);
//  Configure the number of sockets that ZeroMQ will allow. The default
//  is 1024. The actual limit depends on the system, and you can query it
//  by using zsys_socket_limit (). A value of zero means "maximum".
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_set_max_sockets (size_t max_sockets);
//  Return maximum number of ZeroMQ sockets that the system will support.
CZMQ_EXPORT size_t
    zsys_socket_limit (void);
//  Configure the maximum allowed size of a message sent.
//  The default is INT_MAX.
CZMQ_EXPORT void
    zsys_set_max_msgsz (int max_msgsz);
//  Return maximum message size.
CZMQ_EXPORT int
    zsys_max_msgsz (void);
//  Configure the default linger timeout in msecs for new zsock instances.
//  You can also set this separately on each zsock_t instance. The default
//  linger time is zero, i.e. any pending messages will be dropped. If the
//  environment variable ZSYS_LINGER is defined, that provides the default.
//  Note that process exit will typically be delayed by the linger time.
CZMQ_EXPORT void
    zsys_set_linger (size_t linger);
//  Configure the default outgoing pipe limit (HWM) for new zsock instances.
//  You can also set this separately on each zsock_t instance. The default
//  HWM is 1,000, on all versions of ZeroMQ. If the environment variable
//  ZSYS_SNDHWM is defined, that provides the default. Note that a value of
//  zero means no limit, i.e. infinite memory consumption.
CZMQ_EXPORT void
    zsys_set_sndhwm (size_t sndhwm);
//  Configure the default incoming pipe limit (HWM) for new zsock instances.
//  You can also set this separately on each zsock_t instance. The default
//  HWM is 1,000, on all versions of ZeroMQ. If the environment variable
//  ZSYS_RCVHWM is defined, that provides the default. Note that a value of
//  zero means no limit, i.e. infinite memory consumption.
CZMQ_EXPORT void
    zsys_set_rcvhwm (size_t rcvhwm);
//  Configure the default HWM for zactor internal pipes; this is set on both
//  ends of the pipe, for outgoing messages only (sndhwm). The default HWM is
//  1,000, on all versions of ZeroMQ. If the environment var ZSYS_ACTORHWM is
//  defined, that provides the default. Note that a value of zero means no
//  limit, i.e. infinite memory consumption.
CZMQ_EXPORT void
    zsys_set_pipehwm (size_t pipehwm);
//  Return the HWM for zactor internal pipes.
CZMQ_EXPORT size_t
    zsys_pipehwm (void);
//  Configure use of IPv6 for new zsock instances. By default sockets accept
//  and make only IPv4 connections. When you enable IPv6, sockets will accept
//  and connect to both IPv4 and IPv6 peers. You can override the setting on
//  each zsock_t instance. The default is IPv4 only (ipv6 set to 0). If the
//  environment variable ZSYS_IPV6 is defined (as 1 or 0), this provides the
//  default. Note: has no effect on ZMQ v2.
CZMQ_EXPORT void
    zsys_set_ipv6 (int ipv6);
//  Return use of IPv6 for zsock instances.
CZMQ_EXPORT int
    zsys_ipv6 (void);
//  Set network interface name to use for broadcasts, particularly zbeacon.
//  This lets the interface be configured for test environments where required.
//  For example, on Mac OS X, zbeacon cannot bind to 255.255.255.255 which is
//  the default when there is no specified interface. If the environment
//  variable ZSYS_INTERFACE is set, use that as the default interface name.
//  Setting the interface to "*" means "use all available interfaces".
CZMQ_EXPORT void
    zsys_set_interface (const char *value);
//  Return network interface to use for broadcasts, or "" if none was set.
CZMQ_EXPORT const char *
    zsys_interface (void);
//  Set IPv6 address to use zbeacon socket, particularly for receiving zbeacon.
//  This needs to be set IPv6 is enabled as IPv6 can have multiple addresses
//  on a given interface. If the environment variable ZSYS_IPV6_ADDRESS is set,
//  use that as the default IPv6 address.
CZMQ_EXPORT void
    zsys_set_ipv6_address (const char *value);
//  Return IPv6 address to use for zbeacon reception, or "" if none was set.
CZMQ_EXPORT const char *
    zsys_ipv6_address (void);
//  Set IPv6 milticast address to use for sending zbeacon messages. This needs
//  to be set if IPv6 is enabled. If the environment variable
//  ZSYS_IPV6_MCAST_ADDRESS is set, use that as the default IPv6 multicast
//  address.
CZMQ_EXPORT void
    zsys_set_ipv6_mcast_address (const char *value);
//  Return IPv6 multicast address to use for sending zbeacon, or "" if none was
//  set.
CZMQ_EXPORT const char *
    zsys_ipv6_mcast_address (void);
//  Configure the automatic use of pre-allocated FDs when creating new sockets.
//  If 0 (default), nothing will happen. Else, when a new socket is bound, the
//  system API will be used to check if an existing pre-allocated FD with a
//  matching port (if TCP) or path (if IPC) exists, and if it does it will be
//  set via the ZMQ_USE_FD socket option so that the library will use it
//  instead of creating a new socket.
CZMQ_EXPORT void
    zsys_set_auto_use_fd (int auto_use_fd);
//  Return use of automatic pre-allocated FDs for zsock instances.
CZMQ_EXPORT int
    zsys_auto_use_fd (void);
//  Set log identity, which is a string that prefixes all log messages sent
//  by this process. The log identity defaults to the environment variable
//  ZSYS_LOGIDENT, if that is set.
CZMQ_EXPORT void
    zsys_set_logident (const char *value);
//  Set stream to receive log traffic. By default, log traffic is sent to
//  stdout. If you set the stream to NULL, no stream will receive the log
//  traffic (it may still be sent to the system facility).
CZMQ_EXPORT void
    zsys_set_logstream (FILE *stream);
//  Sends log output to a PUB socket bound to the specified endpoint. To
//  collect such log output, create a SUB socket, subscribe to the traffic
//  you care about, and connect to the endpoint. Log traffic is sent as a
//  single string frame, in the same format as when sent to stdout. The
//  log system supports a single sender; multiple calls to this method will
//  bind the same sender to multiple endpoints. To disable the sender, call
//  this method with a null argument.
CZMQ_EXPORT void
    zsys_set_logsender (const char *endpoint);
//  Enable or disable logging to the system facility (syslog on POSIX boxes,
//  event log on Windows). By default this is disabled.
CZMQ_EXPORT void
    zsys_set_logsystem (bool logsystem);
//  Log error condition - highest priority
CZMQ_EXPORT void
    zsys_error (const char *format, ...);
//  Log warning condition - high priority
CZMQ_EXPORT void
    zsys_warning (const char *format, ...);
//  Log normal, but significant, condition - normal priority
CZMQ_EXPORT void
    zsys_notice (const char *format, ...);
//  Log informational message - low priority
CZMQ_EXPORT void
    zsys_info (const char *format, ...);
//  Log debug-level message - lowest priority
CZMQ_EXPORT void
    zsys_debug (const char *format, ...);
//  Self test of this class.
CZMQ_EXPORT void
    zsys_test (bool verbose);
#ifdef CZMQ_BUILD_DRAFT_API
//  *** Draft method, for development use, may change without warning ***
//  Check if default interrupt handler of Ctrl-C or SIGTERM was called.
//  Does not work if ZSYS_SIGHANDLER is false and code does not call
//  set interrupted on signal.
CZMQ_EXPORT bool
    zsys_is_interrupted (void);
//  *** Draft method, for development use, may change without warning ***
//  Set interrupted flag. This is done by default signal handler, however
//  this can be handy for language bindings or cases without default
//  signal handler.
CZMQ_EXPORT void
    zsys_set_interrupted (void);
//  *** Draft method, for development use, may change without warning ***
//  Format a string using printf formatting, returning a freshly allocated
//  buffer. If there was insufficient memory, returns NULL. Free the returned
//  string using zstr_free(). The hinted version allows to optimize by using
//  a larger starting buffer size (known to/assumed by the developer) and so
//  avoid reallocations.
CZMQ_EXPORT char *
    zsys_sprintf_hint (int hint, const char *format, ...);
//  *** Draft method, for development use, may change without warning ***
//  Configure the numeric prefix to each thread created for the internal
//  context's thread pool. This option is only supported on Linux.
//  If the environment variable ZSYS_THREAD_NAME_PREFIX_STR is defined, that
//  provides the default.
//  Note that this method is valid only before any socket is created.
CZMQ_EXPORT void
    zsys_set_thread_name_prefix_str (const char *prefix);
//  *** Draft method, for development use, may change without warning ***
//  Return thread name prefix.
CZMQ_EXPORT const char *
    zsys_thread_name_prefix_str (void);
//  *** Draft method, for development use, may change without warning ***
//  Configure whether to use zero copy strategy in libzmq. If the environment
//  variable ZSYS_ZERO_COPY_RECV is defined, that provides the default.
//  Otherwise the default is 1.
CZMQ_EXPORT void
    zsys_set_zero_copy_recv (int zero_copy);
//  *** Draft method, for development use, may change without warning ***
//  Return ZMQ_ZERO_COPY_RECV option.
CZMQ_EXPORT int
    zsys_zero_copy_recv (void);
//  *** Draft method, for development use, may change without warning ***
//  Configure the threshold value of filesystem object age per st_mtime
//  that should elapse until we consider that object "stable" at the
//  current zclock_time() moment.
//  The default is S_DEFAULT_ZSYS_FILE_STABLE_AGE_MSEC defined in zsys.c
//  which generally depends on host OS, with fallback value of 5000.
CZMQ_EXPORT void
    zsys_set_file_stable_age_msec (int64_t file_stable_age_msec);
//  *** Draft method, for development use, may change without warning ***
//  Return current threshold value of file stable age in msec.
//  This can be used in code that chooses to wait for this timeout
//  before testing if a filesystem object is "stable" or not.
CZMQ_EXPORT int64_t
    zsys_file_stable_age_msec (void);
//  *** Draft method, for development use, may change without warning ***
//  Test if ipv6 is available on the system. Return true if available.
//  The only way to reliably check is to actually open a socket and
//  try to bind it. (ported from libzmq)
CZMQ_EXPORT bool
    zsys_ipv6_available (void);
//  *** Draft method, for development use, may change without warning ***
//  Set IPv4 multicast address to use for sending zbeacon messages. By default
//  IPv4 multicast is NOT used. If the environment variable
//  ZSYS_IPV4_MCAST_ADDRESS is set, use that as the default IPv4 multicast
//  address. Calling this function or setting ZSYS_IPV4_MCAST_ADDRESS
//  will enable IPv4 zbeacon messages.
CZMQ_EXPORT void
    zsys_set_ipv4_mcast_address (const char *value);
//  *** Draft method, for development use, may change without warning ***
//  Return IPv4 multicast address to use for sending zbeacon, or NULL if none was
//  set.
CZMQ_EXPORT const char *
    zsys_ipv4_mcast_address (void);
//  *** Draft method, for development use, may change without warning ***
//  Set multicast TTL default is 1
CZMQ_EXPORT void
    zsys_set_mcast_ttl (byte value);
//  *** Draft method, for development use, may change without warning ***
//  Get multicast TTL
CZMQ_EXPORT byte
    zsys_mcast_ttl (void);
//  *** Draft method, for development use, may change without warning ***
//  Print formatted string. Format is specified by variable names
//  in Python-like format style
//
//  "%(KEY)s=%(VALUE)s", KEY=key, VALUE=value
//  become
//  "key=value"
//
//  Returns freshly allocated string or NULL in a case of error.
//  Not enough memory, invalid format specifier, name not in args
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT char *
    zsys_zprintf (const char *format, zhash_t *args);
//  *** Draft method, for development use, may change without warning ***
//  Return error string for given format/args combination.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT char *
    zsys_zprintf_error (const char *format, zhash_t *args);
//  *** Draft method, for development use, may change without warning ***
//  Print formatted string. Format is specified by variable names
//  in Python-like format style
//
//  "%(KEY)s=%(VALUE)s", KEY=key, VALUE=value
//  become
//  "key=value"
//
//  Returns freshly allocated string or NULL in a case of error.
//  Not enough memory, invalid format specifier, name not in args
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT char *
    zsys_zplprintf (const char *format, zconfig_t *args);
//  *** Draft method, for development use, may change without warning ***
//  Return error string for given format/args combination.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT char *
    zsys_zplprintf_error (const char *format, zconfig_t *args);
#endif // CZMQ_BUILD_DRAFT_API
Please add '@interface' section in '/home/builder/.termux-build/libczmq/src/doc/../src/zsys.c'.

DESCRIPTION

The zsys class provides a portable wrapper for system calls. We collect them here to reduce the number of weird #ifdefs in other classes. As far as possible, the bulk of CZMQ classes are fully portable.

Please add @discuss section in /home/builder/.termux-build/libczmq/src/doc/../src/zsys.c.

EXAMPLE

From zsys_test method.

    zsys_catch_interrupts ();
    //  Check capabilities without using the return value
    int rc = zsys_has_curve ();
    const char *SELFTEST_DIR_RW = "src/selftest-rw";
    if (verbose) {
        char *hostname = zsys_hostname ();
        zsys_info ("host name is %s", hostname);
        freen (hostname);
        zsys_info ("system limit is %zu ZeroMQ sockets", zsys_socket_limit ());
    }
    #ifdef CZMQ_BUILD_DRAFT_API
    zsys_set_file_stable_age_msec (5123);
    assert (zsys_file_stable_age_msec() == 5123);
    zsys_set_file_stable_age_msec (-1);
    assert (zsys_file_stable_age_msec() == 5123);
    #endif // CZMQ_BUILD_DRAFT_API
    zsys_set_linger (0);
    zsys_set_sndhwm (1000);
    zsys_set_rcvhwm (1000);
    zsys_set_pipehwm (2500);
    assert (zsys_pipehwm () == 2500);
    zsys_set_ipv6 (0);
    zsys_set_thread_priority (-1);
    zsys_set_thread_sched_policy (-1);
    zsys_set_thread_name_prefix (0);
    assert (0 == zsys_thread_name_prefix());
    assert (streq ("0", zsys_thread_name_prefix_str()));
    zsys_thread_affinity_cpu_add (0);
    zsys_thread_affinity_cpu_remove (0);
    zsys_set_zero_copy_recv(0);
    assert (0 == zsys_zero_copy_recv());
    zsys_set_zero_copy_recv(1);
    assert (1 == zsys_zero_copy_recv());
    //  Test pipe creation
    zsock_t *pipe_back;
    zsock_t *pipe_front = zsys_create_pipe (&pipe_back);
    zstr_send (pipe_front, "Hello");
    char *string = zstr_recv (pipe_back);
    assert (streq (string, "Hello"));
    freen (string);
    zsock_destroy (&pipe_back);
    zsock_destroy (&pipe_front);
    //  Test file manipulation
    // Don't let anyone fool our workspace
    if (zsys_file_exists ("nosuchfile")) {
        zsys_warning ("zsys_test() had to remove 'nosuchfile' which was not expected here at all");
        zsys_file_delete ("nosuchfile");
    }
    rc = zsys_file_delete ("nosuchfile");
    assert (rc == -1);
    bool rc_bool = zsys_file_exists ("nosuchfile");
    assert (rc_bool != true);
    rc = (int) zsys_file_size ("nosuchfile");
    assert (rc == -1);
    time_t when = zsys_file_modified (".");
    assert (when > 0);
    int mode = zsys_file_mode (".");
    assert (S_ISDIR (mode));
    assert (mode & S_IRUSR);
    assert (mode & S_IWUSR);
    const char *testbasedir  = ".testsys";
    const char *testsubdir  = "subdir";
    char *basedirpath = NULL;   // subdir in a test, under SELFTEST_DIR_RW
    char *dirpath = NULL;       // subdir in a test, under basedirpath
    char *relsubdir = NULL;     // relative short "path" of subdir under testbasedir
    basedirpath = zsys_sprintf ("%s/%s", SELFTEST_DIR_RW, testbasedir);
    assert (basedirpath);
    dirpath = zsys_sprintf ("%s/%s", basedirpath, testsubdir);
    assert (dirpath);
    relsubdir = zsys_sprintf ("%s/%s", testbasedir, testsubdir);
    assert (relsubdir);
    // Normally tests clean up in the end, but if a selftest run dies
    // e.g. on assert(), workspace remains dirty. Better clean it up.
    // We do not really care about results here - we clean up a possible
    // dirty exit of an older build. If there are permission errors etc.
    // the actual tests below would explode.
    if (zsys_file_exists(dirpath)) {
        if (verbose)
            zsys_debug ("zsys_test() has to remove ./%s that should not have been here", dirpath);
        zsys_dir_delete (dirpath);
    }
    if (zsys_file_exists (basedirpath)) {
        if (verbose)
            zsys_debug ("zsys_test() has to remove ./%s that should not have been here", basedirpath);
        zsys_dir_delete (basedirpath);
    }
    // Added tracing because this file-age check fails on some systems
    // presumably due to congestion in a mass-build and valgrind on top
    zsys_file_mode_private ();
    if (verbose)
        printf ("zsys_test() at timestamp %" PRIi64 ": "
            "Creating %s\n",
            zclock_time(), relsubdir );
    rc = zsys_dir_create ("%s/%s", SELFTEST_DIR_RW, relsubdir);
    if (verbose)
        printf ("zsys_test() at timestamp %" PRIi64 ": "
            "Finished creating %s with return-code %d\n",
            zclock_time(), relsubdir, rc );
    assert (rc == 0);
    when = zsys_file_modified (dirpath);
    if (verbose)
        printf ("zsys_test() at timestamp %" PRIi64 ": "
            "Finished calling zsys_file_modified(), got age %jd\n",
            zclock_time(), (intmax_t)when );
    assert (when > 0);
    if (verbose)
        printf ("zsys_test() at timestamp %" PRIi64 ": "
            "Checking if file is NOT stable (is younger than 1 sec)\n",
            zclock_time() );
    assert (!s_zsys_file_stable (dirpath, verbose));
    if (verbose)
        printf ("zsys_test() at timestamp %" PRIi64 ": "
            "Passed the test, file is not stable - as expected\n",
            zclock_time() );
    rc = zsys_dir_delete ("%s/%s", SELFTEST_DIR_RW, relsubdir);
    assert (rc == 0);
    rc = zsys_dir_delete ("%s/%s", SELFTEST_DIR_RW, testbasedir);
    assert (rc == 0);
    zsys_file_mode_default ();
    #if (defined (PATH_MAX))
    char cwd[PATH_MAX];
    #else
    # if (defined (_MAX_PATH))
    char cwd[_MAX_PATH];
    # else
    char cwd[1024];
    # endif
    #endif
    memset (cwd, 0, sizeof(cwd));
    #if (defined (WIN32))
    if (_getcwd(cwd, sizeof(cwd)) != NULL) {
    #else
    if (getcwd(cwd, sizeof(cwd)) != NULL) {
    #endif
        if (verbose)
            printf ("zsys_test() at timestamp %" PRIi64 ": "
                "current working directory is %s\n",
                zclock_time(), cwd);
        assert (zsys_dir_change (SELFTEST_DIR_RW) == 0);
        assert (zsys_dir_change (cwd) == 0);
    }
    else {
        zsys_warning ("zsys_test() : got getcwd() error... "
            "testing zsys_dir_change() anyway, but it can confuse "
            "subsequent tests in this process");
        assert (zsys_dir_change (SELFTEST_DIR_RW) == 0);
    }
    zstr_free (&basedirpath);
    zstr_free (&dirpath);
    zstr_free (&relsubdir);
    // Other subtests
    int major, minor, patch;
    zsys_version (&major, &minor, &patch);
    assert (major == CZMQ_VERSION_MAJOR);
    assert (minor == CZMQ_VERSION_MINOR);
    assert (patch == CZMQ_VERSION_PATCH);
    string = zsys_sprintf ("%s %02x", "Hello", 16);
    assert (streq (string, "Hello 10"));
    freen (string);
    char *str64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890,.";
    int num10 = 1234567890;
    string = zsys_sprintf ("%s%s%s%s%d", str64, str64, str64, str64, num10);
    assert (strlen (string) == (4 * 64 + 10));
    freen (string);
    //  Test logging system
    zsys_set_logident ("czmq_selftest");
    zsys_set_logsender ("inproc://logging");
    void *logger = zsys_socket (ZMQ_SUB, NULL, 0);
    assert (logger);
    rc = zmq_connect (logger, "inproc://logging");
    assert (rc == 0);
    rc = zmq_setsockopt (logger, ZMQ_SUBSCRIBE, "", 0);
    assert (rc == 0);
    if (verbose) {
        zsys_error ("This is an %s message", "error");
        zsys_warning ("This is a %s message", "warning");
        zsys_notice ("This is a %s message", "notice");
        zsys_info ("This is a %s message", "info");
        zsys_debug ("This is a %s message", "debug");
        zsys_set_logident ("hello, world");
        zsys_info ("This is a %s message", "info");
        zsys_debug ("This is a %s message", "debug");
        //  Check that logsender functionality is working
        char *received = zstr_recv (logger);
        assert (received);
        zstr_free (&received);
    }
    zsys_close (logger, NULL, 0);
    {
        // zhash based printf
        zhash_t *args = zhash_new ();
        zhash_insert (args, "key", "value");
        zhash_insert (args, "ham", "spam");
        char *str = zsys_zprintf ("plain string", args);
        assert (streq (str, "plain string"));
        zstr_free (&str);
        str = zsys_zprintf ("%%a%%", args);
        assert (streq (str, "%a%"));
        zstr_free (&str);
        str = zsys_zprintf ("VALUE=%(key)s123", args);
        assert (streq (str, "VALUE=value123"));
        zstr_free (&str);
        str = zsys_zprintf ("VALUE=%(key)s123, %(ham)s, %(ham)s, %%(nospam)s!!!", args);
        assert (streq (str, "VALUE=value123, spam, spam, %(nospam)s!!!"));
        zstr_free (&str);
        str = zsys_zprintf ("VALUE=%(nokey)s123, %(ham)s, %(ham)s, %%(nospam)s!!!", args);
        assert (!str);
        str = zsys_zprintf_error ("VALUE=%(nokey)s123, %(ham)s, %(ham)s, %%(nospam)s!!!", args);
        assert (streq (str, "Key 'nokey' not found in hash"));
        zstr_free (&str);
        str = zsys_zprintf ("VALUE=%(key)s/%%S", args);
        assert (streq (str, "VALUE=value/%S"));
        zstr_free (&str);
        zhash_destroy (&args);
        //ZPL based printf
        zconfig_t *root = zconfig_new ("root", NULL);
        zconfig_put (root, "zsp", "");
        zconfig_put (root, "zsp/return_code", "0");
        str = zsys_zplprintf ("return_code=%(zsp/return_code)s", root);
        assert (streq (str, "return_code=0"));
        zstr_free (&str);
        zconfig_destroy (&root);
    }

AUTHORS

The czmq manual was written by the authors in the AUTHORS file.

RESOURCES

Main web site:

Report bugs to the email <zeromq-dev@lists.zeromq.org[1]>

COPYRIGHT

Copyright (c) the Contributors as noted in the AUTHORS file. This file is part of CZMQ, the high-level C binding for 0MQ: http://czmq.zeromq.org. This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. LICENSE included with the czmq distribution.

NOTES

1.  zeromq-dev@lists.zeromq.org
    mailto:zeromq-dev@lists.zeromq.org