opentemp - create and open a uniquely-named file
int opentemp(char *template, int mode)
by a unique file name, and returns the
address of the template. The template should look like a file name with eleven
trailing The are replaced by a letter followed by the current process id.
Letters from to are tried until the name of a file that does not yet exist
(2)) is generated. Opentemp
then opens the file for
the given mode
and returns the file descriptor. Most calls should use a
mode of ORDWR|ORCLOSE
If no such name can be generated, opentemp
avoids races. Two simultaneous calls to opentemp
never return the same name.