1 files changed, 48 insertions, 0 deletions
diff --git a/sys/fio/mktemp.x b/sys/fio/mktemp.x
new file mode 100644
index 00000000..272d4c64
--- /dev/null
+++ b/sys/fio/mktemp.x
@@ -0,0 +1,48 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<syserr.h>
+
+define	RADIX		26
+define	SZ_SUFFIX	10
+define	NTRIES		5
+define	MAX_TRIP	5000
+
+# MKTEMP -- Make a unique file name (used to generate temporary file names).
+# Format of name is "seedNNNNcc.." where the seed is supplied by the caller,
+# NNNN is (normally) the lowest four digits of the process id, and the
+# characters "cc..." are the radix 26 representation of a local counter
+# (maintained in static storage).  The algorithm used virtually guarantees
+# a unique name on the first try.  Logical directory prefixes are allowed.
+
+procedure mktemp (seed, temp_file, maxchars)
+
+char	seed[ARB], temp_file[ARB], suffix[SZ_SUFFIX]
+int	maxchars, counter, i, n, op, pid
+int	access(), itoc()
+data	counter/0/
+
+begin
+	call zgtpid (pid)				# get process id
+
+	do i = 1, MAX_TRIP {
+	    call strcpy (seed, temp_file, maxchars)
+	    op = itoc (mod(pid,10000), suffix, SZ_SUFFIX)
+	    call strcat (suffix, temp_file, maxchars)
+
+	    counter = counter + 1
+	    op = 1
+	    for (n=counter;  n > 0;  n = (n-1) / RADIX) {
+		suffix[op] = mod (n-1, RADIX) + 'a'
+		op = op + 1
+	    }
+	    suffix[op] = EOS
+	    call strcat (suffix, temp_file, maxchars)
+
+	    if (access (temp_file,0,0) == NO)		# does file exist?
+		return
+	    else if (mod(i,NTRIES) == 0)
+		pid = pid + mod(counter,10)		# not likely to get here
+	}
+
+	call filerr (seed, SYS_FMKTEMP)
+end