Digital UNIX Diffs - vms-process(5) Digital UNIX Diffs - vms-process(5)NAMEvms-process - OpenVMS Process Model Differences
DIFFERENCES
OpenVMS and UNIX both support the concept of processes, however, there
are some major differences in their implementations. Each operating
system allows a user to run multiple concurrent processes by spawning
in OpenVMS and forking in Digital UNIX. The new process is called a
subprocess in OpenVMS and a child in Digital UNIX. Process creation in
Digital UNIX is considerably quicker since the child process is simply
a copy of the parent process. A second step (an exec) is needed to
change the program image that the child runs. On OpenVMS process cre‐
ation includes the loading of a new program image.
To support writing applications that run on both UNIX systems and Open‐
VMS, the OpenVMS runtime libraries include functions that support many
of UNIX C and system services. Due to differences in process models, a
number of the functions related to process creation and management have
semantic differences. The category vms-process(5) describes these dif‐
ferences.
RELATED INFORMATION
Functions: abort(5), atexit(5), creat(5), kill(5), exit(5), open(5),
system(5), vfork(5), exec(5), _exit(5), execl(5), execle(5), execlp(5),
execv(5), execve(5), execvp(5), fopen(5), freopen(5), fdopen(5)CATEGORY INDEXvms-process(5)
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Digital UNIX Diffs - vms-process(5)
