Assigns mask to the current set of masked signals and then waits
    for a signal.

    Format

      #include  <signal.h>

      int sigpause  (int mask);

1 - Argument

 mask

    The signals to be blocked.

2 - Description

    See the sigblock function for information about the mask
    argument.

    When control returns to sigpause, the function restores the
    previous set of masked signals, sets errno to EINTR, and returns
    -1 to indicate an interrupt. The value EINTR is defined in the
    <errno.h> header file.

3 - Return Value

    -1                 Indicates an interrupt. errno is set to EINTR.