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authorJoseph Hunkeler <jhunkeler@gmail.com>2015-07-08 20:46:52 -0400
committerJoseph Hunkeler <jhunkeler@gmail.com>2015-07-08 20:46:52 -0400
commitfa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 (patch)
treebdda434976bc09c864f2e4fa6f16ba1952b1e555 /unix/boot/bootlib/_bytmov.c
downloadiraf-linux-fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4.tar.gz
Initial commit
Diffstat (limited to 'unix/boot/bootlib/_bytmov.c')
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1 files changed, 41 insertions, 0 deletions
diff --git a/unix/boot/bootlib/_bytmov.c b/unix/boot/bootlib/_bytmov.c
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+/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+ */
+
+#define import_spp
+#define import_knames
+#include <iraf.h>
+
+/* BYTMOV -- Byte move from array "a" to array "b". The move must be
+ * nondestructive, allowing a byte array to be shifted left or right a
+ * few bytes, hence comparison of the addresses of the arrays is necessary
+ * to determine if they overlap.
+ */
+void
+BYTMOV (
+ XCHAR *a, /* input byte array */
+ XINT *aoff, /* first byte in A to be moved */
+ XCHAR *b, /* output byte array */
+ XINT *boff, /* first byte in B to be written */
+ XINT *nbytes /* number of bytes to move */
+)
+{
+ register char *ip, *op;
+ register int n = *nbytes;
+ char *ap, *bp;
+
+ ap = (char *)a + (*aoff - 1);
+ bp = (char *)b + (*boff - 1);
+
+ /* If the two arrays are the same return immediately. If the move is
+ * to the left then copy left to right, else copy right to left.
+ */
+ if (ap == bp) {
+ return;
+ } else if (bp < ap) {
+ for (ip=ap, op=bp; --n >= 0; )
+ *op++ = *ip++;
+ } else {
+ for (ip = &ap[n], op = &bp[n]; --n >= 0; )
+ *--op = *--ip;
+ }
+}