date and time created 81/03/02 17:23:27 by wnj

SCCS-vsn: usr.bin/pascal/px_header/px_header.c 1.1

diff --git a/usr/src/usr.bin/pascal/px_header/px_header.c b/usr/src/usr.bin/pascal/px_header/px_header.c
new file mode 100644 (file)
index 0000000..9e57915
--- /dev/null
+++ b/usr/src/usr.bin/pascal/px_header/px_header.c
@@ -0,0 +1,88 @@
+#include <pagsiz.h>
+#include <sys/types.h>
+#include <a.out.h>
+#include "whoami.h"
+#include "objfmt.h"
+
+/*
+ * pxheader - program to sit in front of interpreter code to make shell mods
+ *           unnecessary to make Pascal obj's look like real programs.
+ *
+ * This program lives in /usr/lib/px_header
+ * Bill Joy UCB February 6, 1978
+ */
+static char *sccsid = "@(#)px_header.c 1.1 (Berkeley) %G%";
+
+extern errno;
+
+#define        BUFSIZ  BSIZE
+#define        ETXTBSY 26
+#define        ADDR_LC HEADER_BYTES - sizeof (struct exec) - sizeof (struct pxhdr)
+
+main(argc, argv)
+       register int argc;
+       register char *argv[];
+{
+       register int i, j;
+       register unsigned short *ip;
+       char *largv[512];
+       int pv[2];
+
+       if (argc > 510) {
+               error("Too many arguments.\n");
+               exit(1);
+       }
+       largv[0] = argv[0];
+       largv[1] = "-";
+       for (i = 1; i < argc; i++)
+               largv[i + 1] = argv[i];
+       largv[argc + 1] = 0;
+       pipe(pv);
+       i = fork();
+       if (i == -1)
+               error("Try again.\n");
+       if (i == 0) {
+               close(pv[0]);
+               ip = (unsigned short *) (ADDR_LC);
+               i = ((struct pxhdr *)(ADDR_LC))->objsize + sizeof(struct pxhdr);
+               while (i != 0) {
+                       j = (i > 0 && i < BUFSIZ) ? i : BUFSIZ;
+                       write(pv[1], ip, j);
+                       ip += BUFSIZ / sizeof ( unsigned short );
+                       i -= j;
+               }
+               exit(1);
+       }
+       close(pv[1]);
+       if (pv[0] != 3) {
+               close(3);
+               dup(pv[0]);
+               close(pv[0]);
+       }
+       for (;;) {
+               execv(PX_INTRP, largv);
+               if (errno != ETXTBSY)
+                       break;
+               sleep(2);
+       }
+       error("Px not found.\n");
+}
+
+error(cp)
+       register char *cp;
+{
+       register int i;
+       register char *dp;
+
+       dp = cp;
+       i = 0;
+       while (*dp++)
+               i++;
+       write(2, cp, i);
+       exit(1);
+}
+
+exit(i)
+{
+       _exit(i);
+}