fixes #112 add support for if "==" echo Hello and similar IF constructs

supports properly quoted strings with delimeters, otherwise stops on left an right side of == after first delimiter character and allows junk characters to left of == (but not right of it, e.g. garbage== but not ==garbage) and updates tst-if.bat

Author: PerditionC

cmd/if.c

@@ -148,34 +148,41 @@ int cmd_if(char *param)
 
 	/* Check that '==' is present, syntax error if not */
 	else {
-		size_t len;
+		size_t len_l, len_r;
 		char *r;      /* right operand */
 
 		pp = skipqword(param, "==");
 
+        /* skip past any garbage characters before the == */
+        while (*pp && (*pp != '=') && !isargdelim(*pp)) pp++;
+
 		if(*pp != '=' || pp[1] != '=') {
 			error_syntax(0);
 			return 0;
 		}
 
 		*pp = '\0';     /* param[] points to the left operand */
 
-		/* skip over the '==' and subsquent spaces and
-			assign the end of the right operator to pp */
-		pp = skipqword(r = ltrimcl(pp + 2), 0);
+		/* skip over the '==' and subsquent spaces */
+        r = ltrimcl(pp + 2);
+        /* and assign the end of the right operator to pp */
+		pp = skipqword(r, 0);
 
 		/*	now: param := beginning of the left operand
 			r := beginning of the right operand
 			pp := end of right operand
 		*/
 
 		rtrimcl(param);      /* ensure that spurious whitespaces are ignored */
-		len = strlen(param);
+		len_l = strlen(param);
+		len_r = strlen(r);
+		dprintf(("left side=[%s] %i\n", param, len_l));
+		dprintf(("rigt side=[%s] %i\n", r, len_r));
 
 		/* check if strings differ */
-		if ( ((pp - r) == len) &&
-		     ((ignore_case && strnicmp(param, r, len) == 0) ||
-		      (memcmp(param, r, len) == 0)) )
+		if ( (len_l == len_r) &&
+		     ((ignore_case && strnicmp(param, r, len_l) == 0) ||
+		      (memcmp(param, r, len_l) == 0)) )
 			x_flag = X_EXEC;
 	}
 

include/cmdline.h

@@ -88,7 +88,7 @@ typedef int (* const optScanner)(const char * const optstr, int ch, int bool, co
 #define optLong(str)  (strcmpi(optstr, (str)) == 0)
 
 
-char *skipqword(const char *str, const char * const stop);
+char *skipqword(char *str, const char * const stop);
 
 /* Use matchtok() to compare string constants */
 #define match(line,word,len) match_(&(line), (word), (len))

lib/skqwd.c

@@ -56,6 +56,7 @@
 #include "../include/command.h"
 #include "../include/cmdline.h"
 
+#if 0
 char *skipqword(const char *pp, const char * const stop)
 {	size_t len;
 	int quote = 0;
@@ -74,3 +75,51 @@ char *skipqword(const char *pp, const char * const stop)
 
 	return (char *) pp;		/* strip const */
 }
+#else
+char *skipqword(char *pp, const char * const stop)
+{	size_t len;
+	int quote = 0;
+	char *pp_trunc = 0;
+
+	len = stop? strlen(stop): 0;
+
+	if(*pp) do {
+        /* if we find a quote then continue until terminator or end of string found */
+		if(quote) {
+			if(quote == *pp) {
+                pp_trunc = 0;
+				quote = 0;
+            } else if(len && (memcmp(pp, stop, len) == 0)) {
+                /* no matching quote, so back up to delimiter and mark end of pp */
+				char *p = pp;
+				while(*p && (!quote || (quote != *p)) && !isargdelim(*p)) p--;
+                p++;
+                if (p < pp) *p='\0';
+                break;
+            } else if(!pp_trunc && isargdelim(*pp)) {
+                pp_trunc = pp; /* if end of string but no matching quote, terminate at 1st delimiter instead */
+            }
+		} else if(strchr(QUOTE_STR, *pp))
+			quote = *pp;
+		else if(len && (memcmp(pp, stop, len) == 0)) {
+                /* no matching quote, so back up to delimiter and mark end of pp */
+				char *p = pp;
+				while(*p && (!quote || (quote != *p)) && !isargdelim(*p)) p--;
+                p++;
+                if (p < pp) *p='\0';
+                break;
+        } else if(!pp_trunc && isargdelim(*pp)) {
+            pp_trunc = pp;  /* truncate at delimter if not in quoted string */
+			break;
+        }
+	} while(*++pp);
+	if (pp_trunc) {
+        *pp_trunc = '\0'; /* never found end of quote so stop at first delimiter */
+        dprintf(("returning [%s]\n", pp_trunc+1));
+        return pp_trunc+1;
+    }
+
+    dprintf(("returning [%s]\n", pp));
+	return (char *) pp;		/* strip const */
+}
+#endif

tests/tst-if.bat

@@ -65,8 +65,9 @@ if 1== 1 echo Probe #9 passed
 if 1== 2 echo Probe #10 failed
 if not 1=="1" echo Probe #11 passed
 if not "1 2 3 4"=="1 2 3 4" echo Probe #12 failed
+if "1 2 3 4"=="1 2 3 4" echo Probe #13 passed
 echo.
-echo You should see passed probes 1, 3, 5, 7, 9,& 11 and no failed one
+echo You should see passed probes 1, 3, 5, 7, 9, 11,& 13 and no failed one
 echo.
 pause
 
@@ -100,5 +101,20 @@ if a==a
 echo.
 pause
 
+cls
+echo Testing " and extra characters included with ==
+echo .
+if "a=="a echo Probe #1 passed
+if "a == "a echo Probe #2 passed
+if a "== a echo Probe #3 passed
+if a garbage== a echo Probe #4 passed
+if a garbage==garbage a echo Probe #5 failed
+if .a == .a echo Probe #6 passed
+if " a==" a echo Probe #7 failed, a is not a valid command
+if " echo==" echo Probe #8 passed
+echo .
+echo You should see passed probes 1,2,3,4,6,& 8 with 7 giving a bad command error
+pause
+
 echo.
 echo Test finished