Add PQescapeIdentifier() to libpq

Christopher Kings-Lynne

3 files changed, 43 insertions, 3 deletions

diff --git a/src/interfaces/libpq/exports.txt b/src/interfaces/libpq/exports.txt
index 84fe637c82b..37655638434 100644
--- a/src/interfaces/libpq/exports.txt
+++ b/src/interfaces/libpq/exports.txt
@@ -1,4 +1,4 @@
-# $PostgreSQL: pgsql/src/interfaces/libpq/exports.txt,v 1.11 2006/05/28 22:42:05 tgl Exp $
+# $PostgreSQL: pgsql/src/interfaces/libpq/exports.txt,v 1.12 2006/06/27 00:03:41 momjian Exp $
 # Functions to be exported by libpq DLLs
 PQconnectdb               1
 PQsetdbLogin              2
@@ -130,3 +130,5 @@ PQescapeByteaConn         127
 PQencryptPassword         128
 PQisthreadsafe            129
 enlargePQExpBuffer        130
+PQescapeIdentifier        131
+
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 69da7bc34c5..76981fa0d1e 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.186 2006/05/28 21:13:54 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.187 2006/06/27 00:03:41 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2516,6 +2516,42 @@ PQescapeString(char *to, const char *from, size_t length)
 }
 
 /*
+ * Escaping arbitrary strings to get valid SQL identifier strings.
+ *
+ * Replaces " with "".
+ *
+ * length is the length of the source string.  (Note: if a terminating NUL
+ * is encountered sooner, PQescapeIdentifier stops short of "length"; the behavior
+ * is thus rather like strncpy.)
+ *
+ * For safety the buffer at "to" must be at least 2*length + 1 bytes long.
+ * A terminating NUL character is added to the output string, whether the
+ * input is NUL-terminated or not.
+ *
+ * Returns the actual length of the output (not counting the terminating NUL).
+ */
+size_t
+PQescapeIdentifier(char *to, const char *from, size_t length)
+{
+	const char *source = from;
+	char	   *target = to;
+	size_t		remaining = length;
+
+	while (remaining > 0 && *source != '\0')
+	{
+		if (*source  == '"')
+			*target++ = *source;
+		*target++ = *source++;
+		remaining--;
+	}
+
+	/* Write the terminating NUL character. */
+	*target = '\0';
+
+	return target - to;
+}
+
+/*
  *		PQescapeBytea	- converts from binary string to the
  *		minimal encoding necessary to include the string in an SQL
  *		INSERT statement with a bytea type column as the target.
diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index 3b824efe852..272ccc87deb 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-fe.h,v 1.129 2006/05/23 22:13:19 momjian Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-fe.h,v 1.130 2006/06/27 00:03:42 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -436,6 +436,8 @@ extern unsigned char *PQescapeByteaConn(PGconn *conn,
 				  size_t *to_length);
 extern unsigned char *PQunescapeBytea(const unsigned char *strtext,
 				size_t *retbuflen);
+extern size_t PQescapeIdentifier(char *to, const char *from, size_t length);
+
 /* These forms are deprecated! */
 extern size_t PQescapeString(char *to, const char *from, size_t length);
 extern unsigned char *PQescapeBytea(const unsigned char *from, size_t from_length,