I have made some corrections to my previous patches for retrieving array

attributes as tcl arrays.  The previous code had problems with some chars
used as delimiter by Tcl.  The new code should be more robust.

By: Massimo Dal Zotto <dz@cs.unitn.it>

diff --git a/src/interfaces/libpgtcl/pgtclCmds.c b/src/interfaces/libpgtcl/pgtclCmds.c
index dca92137cfe9f0af59c9c182d6a18807f7ea59ca..87b926805e521077c8ce810ee2b68ea3fdde38a4 100644 (file)
--- a/src/interfaces/libpgtcl/pgtclCmds.c
+++ b/src/interfaces/libpgtcl/pgtclCmds.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/interfaces/libpgtcl/Attic/pgtclCmds.c,v 1.2 1996/07/23 03:38:44 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/interfaces/libpgtcl/Attic/pgtclCmds.c,v 1.3 1996/09/16 05:54:53 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,6 +23,192 @@
 #include "pgtclCmds.h"
 #include "pgtclId.h"
 
+#ifdef TCL_ARRAYS
+#define ISOCTAL(c)     (((c) >= '0') && ((c) <= '7'))
+#define DIGIT(c)       ((c) - '0')
+
+/*
+ * translate_escape() --
+ *
+ * This function performs in-place translation of a single C-style
+ * escape sequence pointed by p. Curly braces { } and double-quote
+ * are left escaped if they appear inside an array.
+ * The value returned is the pointer to the last character (the one
+ * just before the rest of the buffer).
+ */
+
+static inline char*
+translate_escape(char *p, int isArray)
+{
+    register char c, *q, *s;
+
+#ifdef DEBUG_ESCAPE
+    printf("   escape = '%s'\n", p);
+#endif
+    /* Address of the first character after the escape sequence */
+    s = p+2;
+    switch (c = *(p+1)) {
+      case '0':
+      case '1':
+      case '2':
+      case '3':
+      case '4':
+      case '5':
+      case '6':
+      case '7':
+       c = DIGIT(c);
+       if (ISOCTAL(*s)) {
+           c = (c<<3) + DIGIT(*s++);
+       }
+       if (ISOCTAL(*s)) {
+           c = (c<<3) + DIGIT(*s++);
+       }
+       *p = c;
+       break;
+      case 'b':
+       *p = '\b';
+       break;
+      case 'f':
+       *p = '\f';
+       break;
+      case 'n':
+       *p = '\n';
+       break;
+      case 'r':
+       *p = '\r';
+       break;
+      case 't':
+       *p = '\t';
+       break;
+      case 'v':
+       *p = '\v';
+       break;
+      case '\\':
+      case '{':
+      case '}':
+      case '"':
+       /*
+        * Backslahes, curly braces and double-quotes are left
+        * escaped if they appear inside an array. They will be
+        * unescaped by Tcl in Tcl_AppendElement.
+        * The buffer position is advanced by 1 so that the this
+        * character is not processed again by the caller.
+        */
+       if (isArray) {
+           return p+1;
+       } else {
+           *p = c;
+       }
+       break;
+      case '\0':
+       /*
+        * This means a backslash at the end of the string.
+        * It should never happen but in that case replace
+        * the \ with a \0 but don't shift the rest of the
+        * buffer so that the caller can see the end of the
+        * string and terminate.
+        */
+       *p = c;
+       return p;
+       break;
+      default:
+       /*
+        * Default case, store the escaped character over the backslash
+        * and shift the buffer over itself.
+        */
+       *p = c;
+    }
+    /* Shift the rest of the buffer over itself after the current char */
+    q = p+1;
+    for ( ; *s ; ) {
+       *q++ = *s++;
+    }
+    *q = '\0';
+#ifdef DEBUG_ESCAPE
+    printf("   after  = '%s'\n", p);
+#endif
+    return p;
+}
+
+/*
+ * tcl_value() --
+ *
+ * This function does in-line conversion of a value returned by libpq
+ * into a tcl string or into a tcl list if the value looks like the
+ * representation of a postgres array.
+ */
+
+static char *
+tcl_value (char *value)
+{
+    int literal, last;
+    register char c, *p, *q, *s;
+
+    if (!value) {
+       return ((char *) NULL);
+    }
+
+#ifdef DEBUG
+    printf("pq_value  = '%s'\n", value);
+#endif
+    last = strlen(value)-1;
+    if ((last >= 1) && (value[0] == '{') && (value[last] == '}')) {
+       /* Looks like an array, replace ',' with spaces */
+       /* Remove the outer pair of { }, the last first! */
+       value[last] = '\0';
+       value++;
+       literal = 0;
+       for (p=value; *p; p++) {
+           if (!literal) {
+               /* We are at the list level, look for ',' and '"' */
+               switch (*p) {
+                 case '"':     /* beginning of literal */
+                   literal = 1;
+                   break;
+                 case ',':     /* replace the ',' with space */
+                   *p = ' ';
+                   break;
+               }
+           } else {
+               /* We are inside a C string */
+               switch (*p) {
+                 case '"':     /* end of literal */
+                   literal = 0;
+                   break;
+                 case '\\':
+                   /*
+                    * escape sequence, translate it
+                    */
+                   p = translate_escape(p,1);
+                   break;
+               }
+           }
+           if (!*p) {
+               break;
+           }
+       }
+    } else {
+       /* Looks like a normal scalar value */
+       for (p=value; *p; p++) {
+           if (*p == '\\') {
+               /*
+                * escape sequence, translate it
+                */
+               p = translate_escape(p,0);
+           }
+           if (!*p) {
+               break;
+           }
+       }
+    }
+#ifdef DEBUG
+    printf("tcl_value = '%s'\n\n", value);
+#endif
+    return (value);
+}
+
+#endif
+
 /**********************************
  * pg_connect
  make a connection to a backend.  
@@ -264,7 +450,11 @@ Pg_result(ClientData cData, Tcl_Interp *interp, int argc, char* argv[])
            for (i=0;i<PQnfields(result);i++) {
                sprintf(arrayInd, "%d,%s", tupno, PQfname(result,i));
                Tcl_SetVar2(interp, arrVar, arrayInd, 
+#ifdef TCL_ARRAYS
+                           tcl_value(PQgetvalue(result,tupno,i)),
+#else
                            PQgetvalue(result,tupno,i),
+#endif
                            TCL_LEAVE_ERR_MSG);
            }
        }
@@ -304,12 +494,19 @@ Pg_result(ClientData cData, Tcl_Interp *interp, int argc, char* argv[])
            return TCL_ERROR;
        }
 
+#ifdef TCL_ARRAYS
+       for (i=0; i<PQnfields(result); i++) {
+           Tcl_AppendElement(interp, tcl_value(PQgetvalue(result,tupno,i)));
+       }
+#else
 /*     Tcl_AppendResult(interp, PQgetvalue(result,tupno,0),NULL); */
         Tcl_AppendElement(interp, PQgetvalue(result,tupno,0));
        for (i=1;i<PQnfields(result);i++) {
 /*       Tcl_AppendResult(interp, " ", PQgetvalue(result,tupno,i),NULL);*/
          Tcl_AppendElement(interp, PQgetvalue(result,tupno,i));
        }
+#endif
+
        return TCL_OK;
     }
     else if (strcmp(opt, "-attributes") == 0) {