This is a set of single row character functions, defined for the datatype

text, which are supposed to behave exactly as their Oracle counterparts.

From: Edmund Mergl <E.Mergl@bawue.de>

src/backend/utils/adt/oracle_compat.c

@@ -0,0 +1,420 @@
+/*
+ *  Edmund Mergl <E.Mergl@bawue.de>
+ *
+ *  $Id: oracle_compat.c,v 1.1 1997/03/04 05:32:06 scrappy Exp $
+ *
+ */
+
+
+#include <ctype.h>
+#include "postgres.h"
+
+
+/********************************************************************
+ *
+ * lower
+ *
+ * Syntax:
+ *
+ *   text *lower(text *string)
+ *
+ * Purpose:
+ *
+ *   Returns string, with all letters forced to lowercase.
+ *
+ ********************************************************************/
+
+text *
+lower(text *string)
+{
+  char *ptr;
+  int m;
+
+  m = VARSIZE(string) - VARHDRSZ;
+
+  if (m <= 0) {
+    return string;
+  }
+
+  ptr = VARDATA(string);
+
+  while (m--) {
+    *ptr = tolower(*ptr);
+    ++ptr;
+  }
+
+  return string;
+}
+
+
+/********************************************************************
+ *
+ * upper
+ *
+ * Syntax:
+ *
+ *   text *upper(text *string)
+ *
+ * Purpose:
+ *
+ *   Returns string, with all letters forced to uppercase.
+ *
+ ********************************************************************/
+
+text *
+upper(text *string)
+{
+  char *ptr;
+  int m;
+
+  m = VARSIZE(string) - VARHDRSZ;
+
+  if (m <= 0) {
+    return string;
+  }
+
+  ptr = VARDATA(string);
+
+  while (m--) {
+    *ptr = toupper(*ptr);
+    ++ptr;
+  }
+
+  return string;
+}
+
+
+/********************************************************************
+ *
+ * initcap
+ *
+ * Syntax:
+ *
+ *   text *initcap(text *string)
+ *
+ * Purpose:
+ *
+ *   Returns string, with first letter of each word in uppercase,
+ *   all other letters in lowercase. A word is delimited by white
+ *   space.
+ *
+ ********************************************************************/
+
+text *
+initcap(text *string)
+{
+  char *ptr;
+  int m;
+
+  m = VARSIZE(string) - VARHDRSZ;
+
+  if (m <= 0) {
+    return string;
+  }
+
+  ptr = VARDATA(string);
+
+  *ptr = toupper(*ptr);
+  ++ptr;
+  --m;
+
+  while (m--) {
+    if (*(ptr - 1) == ' ' || *(ptr - 1) == '	') {
+      *ptr = toupper(*ptr);
+    } else {
+      *ptr = tolower(*ptr);
+    }
+    ++ptr;
+  }
+
+  return string;
+}
+
+
+/********************************************************************
+ *
+ * lpad
+ *
+ * Syntax:
+ *
+ *   text *lpad(text *string1, int4 len, text *string2)
+ *
+ * Purpose:
+ *
+ *   Returns string1, left-padded to length len with the sequence of
+ *   characters in string2.
+ *
+ ********************************************************************/
+
+text *
+lpad(text *string1, int4 len, text *string2)
+{
+  text *ret;
+  char *ptr, *ptr1, *ptr2;
+  int m, n;
+
+  m = len - VARSIZE(string1) + VARHDRSZ;
+
+  if (m <= 0 || (VARSIZE(string2) - VARHDRSZ) <= 0) {
+    return string1;
+  }
+
+  ret = (text *)malloc(VARHDRSZ + len);
+  VARSIZE(ret) = VARHDRSZ + len;
+
+  ptr   = VARDATA(ret);
+  ptr2  = VARDATA(string2);
+
+  while (m--) {
+    *ptr++ = *ptr2;
+    ptr2 = ptr2 == VARDATA(string2) + VARSIZE(string2) - VARHDRSZ - 1 ? VARDATA(string2) : ++ptr2;
+  }
+
+  n    = VARSIZE(string1) - VARHDRSZ;
+  ptr1 = VARDATA(string1);
+
+  while (n--) {
+    *ptr++ = *ptr1++;
+  }
+
+  return ret;
+}
+
+
+/********************************************************************
+ *
+ * rpad
+ *
+ * Syntax:
+ *
+ *   text *rpad(text *string1, int4 len, text *string2)
+ *
+ * Purpose:
+ *
+ *   Returns string1, right-padded to length len with the sequence of
+ *   characters in string2.
+ *
+ ********************************************************************/
+
+text *
+rpad(text *string1, int4 len, text *string2)
+{
+  text *ret;
+  char *ptr, *ptr1, *ptr2;
+  int m, n;
+
+  m = len - VARSIZE(string1) + VARHDRSZ;
+
+  if (m <= 0 || (VARSIZE(string2) - VARHDRSZ) <= 0) {
+    return string1;
+  }
+
+  ret = (text *)malloc(VARHDRSZ + len);
+  VARSIZE(ret) = VARHDRSZ + len;
+
+  n    = VARSIZE(string1) - VARHDRSZ;
+  ptr  = VARDATA(ret);
+  ptr1 = VARDATA(string1);
+
+  while (n--) {
+    *ptr++ = *ptr1++;
+  }
+
+  ptr2  = VARDATA(string2);
+
+  while (m--) {
+    *ptr++ = *ptr2;
+    ptr2 = ptr2 == VARDATA(string2) + VARSIZE(string2) - VARHDRSZ - 1 ? VARDATA(string2) : ++ptr2;
+  }
+
+  return ret;
+}
+
+
+/********************************************************************
+ *
+ * ltrim
+ *
+ * Syntax:
+ *
+ *   text *ltrim(text *string, text *set)
+ *
+ * Purpose:
+ *
+ *   Returns string with initial characters removed up to the first
+ *   character not in set.
+ *
+ ********************************************************************/
+
+text *
+ltrim(text *string, text *set)
+{
+  char *ptr, *ptr2, *end2;
+  int m;
+
+  m = VARSIZE(string) - VARHDRSZ;
+
+  if (m <= 0 || VARSIZE(set) - VARHDRSZ <= 0) {
+    return string;
+  }
+
+  ptr  = VARDATA(string);
+  ptr2 = VARDATA(set);
+  end2 = VARDATA(set) + VARSIZE(set) - VARHDRSZ - 1;
+  
+  while (m--) {
+    while (ptr2 <= end2) {
+      if (*ptr == *ptr2) {
+        break;
+      }
+      ++ptr2;
+    }
+    if (*ptr != *ptr2) {
+      break;
+    }
+    ++ptr;
+    ptr2 = VARDATA(set);
+  }
+
+  m    = VARDATA(string) + VARSIZE(string) - VARHDRSZ - ptr + 1;
+  ptr2 = VARDATA(string);
+
+  while (m--) {
+    *ptr2++ = *ptr++;
+  }
+
+  VARSIZE(string) -= ptr - ptr2;
+
+  return string;
+}
+
+
+/********************************************************************
+ *
+ * rtrim
+ *
+ * Syntax:
+ *
+ *   text *rtrim(text *string, text *set)
+ *
+ * Purpose:
+ *
+ *   Returns string with final characters removed after the last
+ *   character not in set.
+ *
+ ********************************************************************/
+
+text *
+rtrim(text *string, text *set)
+{
+  char *ptr, *ptr2, *end2;
+  int m;
+
+  m = VARSIZE(string) - VARHDRSZ;
+
+  if (m <= 0 || VARSIZE(set) - VARHDRSZ <= 0) {
+    return string;
+  }
+
+  ptr   = VARDATA(string) + VARSIZE(string) - VARHDRSZ - 1;
+  ptr2  = VARDATA(set);
+  end2  = VARDATA(set)    + VARSIZE(set)    - VARHDRSZ - 1;
+  
+  while (m--) {
+    while (ptr2 <= end2) {
+      if (*ptr == *ptr2) {
+        break;
+      }
+      ++ptr2;
+    }
+    if (*ptr != *ptr2) {
+      break;
+    }
+    --ptr;
+    ptr2 = VARDATA(set);
+  }
+
+  VARSIZE(string) -= VARDATA(string) + VARSIZE(string) - VARHDRSZ - 1 - ptr;
+
+  return string;
+}
+
+
+/********************************************************************
+ *
+ * substr
+ *
+ * Syntax:
+ *
+ *   text *substr(text *string, int4 m, int4 n)
+ *
+ * Purpose:
+ *
+ *   Returns a portion of string, beginning at character m, n
+ *   characters long. The first position of string is 1.
+ *
+ ********************************************************************/
+
+text *
+substr(text *string, int4 m, int4 n)
+{
+  char *ptr, *ptr1;
+  int len;
+
+  len = VARSIZE(string) - VARHDRSZ - m;
+
+  if (m <= 0 || n <= 0 || len <= 0) {
+    return string;
+  }
+
+  ptr  = VARDATA(string);
+  ptr1 = ptr + m - 1;
+  len  = len + 1 < n ? len + 1 : n;
+
+  while (len--) {
+    *ptr++ = *ptr1++;
+  }
+
+  VARSIZE(string) -= ptr1 - ptr;
+
+  return string;
+}
+
+
+/********************************************************************
+ *
+ * translate
+ *
+ * Syntax:
+ *
+ *   text *translate(text *string, char from, char to)
+ *
+ * Purpose:
+ *
+ *   Returns string after replacing all occurences of from with
+ *   the corresponding character in to. TRANSLATE will not remove
+ *    characters.
+ *
+ ********************************************************************/
+
+text *
+translate(text *string, char from, char to)
+{
+  char *ptr;
+  int m;
+
+  m   = VARSIZE(string) - VARHDRSZ;
+  ptr = VARDATA(string);
+
+  while (m--) {
+    if (*ptr == from) {
+      *ptr = to;
+    }
+    ++ptr;
+  }
+
+  return string;
+}
+
+
+/* EOF */