1 files changed, 100 insertions, 0 deletions
diff --git a/sys/osb/strsum.c b/sys/osb/strsum.c
new file mode 100644
index 00000000..71655b3f
--- /dev/null
+++ b/sys/osb/strsum.c
@@ -0,0 +1,100 @@
+#define	import_spp
+#define import_knames
+#include <iraf.h>
+
+
+#ifdef INT32_SUM
+
+/**
+ *  STRSUM -- Compute the 32-bit checksum of an SPP string.
+ */
+
+int
+STRSUM (XCHAR *array, XINT *length, XINT *maxch)
+{
+    int      i, len, carry=0, newcarry=0;
+    unsigned int *iarray, sum = 0;
+    char     pkstr[*maxch];
+
+    register int     n = *maxch;
+    register XCHAR  *ip = array;
+    register char   *op = (char *) pkstr;
+
+
+    /*  Convert the input string to a packed char array.
+     */
+    while ((*op++ = *ip++) != XEOS && --n >= 0)
+	;
+    *--op = EOS;
+
+    /*  Compute the checksum.
+     */
+    iarray = (unsigned int *) pkstr;
+    len = *length / 4;
+
+    for (i=0; i<len; i++) {
+        if (iarray[i] > ~ sum)
+            carry++;
+
+        sum += iarray[i];
+    }
+
+    while (carry) {
+        if (carry > ~ sum)
+            newcarry++;
+        sum += carry;
+        carry = newcarry;
+        newcarry = 0;
+    }
+
+    return (sum);
+}
+
+#else
+
+/**
+ *  STRSUM -- Compute the 32-bit checksum of an SPP string.
+ */
+
+int
+STRSUM (XCHAR *array, XINT *length, XINT *maxch)
+{
+    int      i, len, carry=0, newcarry=0;
+    unsigned int *iarray, sum = 0;
+    unsigned long lsum = 0;
+    char     pkstr[*maxch];
+
+    register int     n = *maxch;
+    register XCHAR  *ip = array;
+    register char   *op = (char *) pkstr;
+
+
+    /*  Convert the input string to a packed char array.
+     */
+    while ((*op++ = *ip++) != XEOS && --n >= 0)
+	;
+    *--op = EOS;
+
+    /*  Compute the checksum.
+     */
+    iarray = (unsigned int *) pkstr;
+    len = *length / 4;
+
+    for (i=0; i<len; i++) {
+        if (iarray[i] > ~ lsum)
+            carry++;
+        lsum += iarray[i];
+    }
+
+    while (carry) {
+        if (carry > ~ lsum)
+            newcarry++;
+        lsum += carry;
+        carry = newcarry;
+        newcarry = 0;
+    }
+
+    return (abs(sum = lsum));
+}
+
+#endif