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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-B58D282E-E6EC-4AE1-96DB-30A5FB850563" xml:lang="en"><title><codeph>exec()</codeph> without

    13 forking using <apiname>posix_spawn()</apiname></title><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>A UNIX® program may exec without forking. The result is that the calling

    15 process executes another binary, but inherits certain properties, for example,

    16 file descriptors.  </p>

    17 <p>The P.I.P.S. equivalent would be to call <xref href="GUID-E7C4DE71-BC5B-34AE-ACB3-C34A0DB1FC16.dita"><apiname>posix_spawn()</apiname></xref> and

    18 pass any inherited data via <codeph>argv</codeph> parameters.  </p>

    19 <p>Note that if a parent process is waiting for the child to terminate then

    20 the termination of the newly created task must be synchronised. Therefore

    21 a <xref href="GUID-8F5C89A4-7813-32C7-973E-F7F0F3690BC6.dita"><apiname>waitpid()</apiname></xref> call should follow the <xref href="GUID-E7C4DE71-BC5B-34AE-ACB3-C34A0DB1FC16.dita"><apiname>posix_spawn()</apiname></xref> call

    22 so that it does not exit prematurely. Otherwise <xref href="GUID-FED685F4-5FAD-39F4-9812-3B0A85D8718C.dita"><apiname>exit()</apiname></xref> can

    23 be called after the posix_spawn().  </p>

    24 <p>Also, note that if the process which formerly executed and

    25 which now uses <xref href="GUID-E7C4DE71-BC5B-34AE-ACB3-C34A0DB1FC16.dita"><apiname>posix_spawn()</apiname></xref> stores its PID (for example,

    26 in the file system) to allow other processes to target it, then care must

    27 be taken to store the relevant PID (Process ID). This is because the PID for

    28 the newly spawned process may need to be stored instead.</p>

    29 </conbody></concept>