arithmetic

SCCS-vsn: bin/sh/expand.c 5.2

diff --git a/usr/src/bin/sh/expand.c b/usr/src/bin/sh/expand.c
index 9885492..2121550 100644 (file)
--- a/usr/src/bin/sh/expand.c
+++ b/usr/src/bin/sh/expand.c
@@ -9,7 +9,7 @@
  */
 
 #ifndef lint
  */
 
 #ifndef lint

-static char sccsid[] = "@(#)expand.c   5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)expand.c   5.2 (Berkeley) %G%";

 #endif /* not lint */
 
 /*
 #endif /* not lint */
 
 /*


@@ -33,6 +33,7 @@ static char sccsid[] = "@(#)expand.c  5.1 (Berkeley) %G%";
 #include "error.h"
 #include "mystring.h"
 #include <sys/types.h>
 #include "error.h"
 #include "mystring.h"
 #include <sys/types.h>

+#include <sys/time.h>

 #include <sys/stat.h>
 #include <errno.h>
 #include <dirent.h>
 #include <sys/stat.h>
 #include <errno.h>
 #include <dirent.h>


@@ -184,11 +185,12 @@ argstr(p, full)
        register char *p;
        {
        char c;
        register char *p;
        {
        char c;

+       int sawari = 0;

 
        for (;;) {
                switch (c = *p++) {
                case '\0':
 
        for (;;) {
                switch (c = *p++) {
                case '\0':

-               case CTLENDVAR:
+               case CTLENDVAR: /* ??? */

                        goto breakloop;
                case CTLESC:
                        if (full)
                        goto breakloop;
                case CTLESC:
                        if (full)


@@ -204,6 +206,9 @@ argstr(p, full)
                        expbackq(argbackq->n, c & CTLQUOTE, full);
                        argbackq = argbackq->next;
                        break;
                        expbackq(argbackq->n, c & CTLQUOTE, full);
                        argbackq = argbackq->next;
                        break;

+               case CTLENDARI:
+                       expari();
+                       break;

                default:
                        STPUTC(c, expdest);
                }
                default:
                        STPUTC(c, expdest);
                }


@@ -211,6 +216,45 @@ argstr(p, full)
 breakloop:;
 }
 
 breakloop:;
 }
 

+/*
+ * Expand arithmetic expression.  Backup to start of expression,
+ * evaluate, place result in (backed up) result, adjust string position.
+ */
+expari()
+{
+       char *p, *start = stackblock();
+       int result;
+
+       /*
+        * This routine is slightly over-compilcated for
+        * efficiency.  First we make sure there is
+        * enough space for the result, which may be bigger
+        * than the expression if we add exponentation.  Next we
+        * scan backwards looking for the start of arithmetic.  If the
+        * next previous character is a CTLESC character, then we
+        * have to rescan starting from the beginning since CTLESC
+        * characters have to be processed left to right.  
+        */
+       CHECKSTRSPACE(8, expdest);
+       USTPUTC('\0', expdest);
+       p = expdest;
+       while (*p != CTLARI && p >= start)
+               --p;
+       if (*p != CTLARI)
+               error("missing CTLARI (shouldn't happen)");
+       if (p > start && *(p-1) == CTLESC)
+               for (p = start; *p != CTLARI; p++)
+                       if (*p == CTLESC)
+                               p++;
+       rmescapes(p+1);
+       result = arith(p+1);
+       fmtstr(p, 10, "%d", result);
+       while (*p++)
+               ;
+       result = expdest - p + 1;
+       STADJUST(-result, expdest);
+}
+

 
 /*
  * Expand stuff in backwards quotes.
 
 /*
  * Expand stuff in backwards quotes.