Major psql overhaul by Peter Eisentraut.

1 files changed, 132 insertions, 0 deletions

diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
new file mode 100644
index 00000000000..ea824cff691
--- /dev/null
+++ b/src/bin/psql/variables.c
@@ -0,0 +1,132 @@
+#include <config.h>
+#include <c.h>
+#include "variables.h"
+
+#include <stdlib.h>
+#include <assert.h>
+
+
+VariableSpace CreateVariableSpace(void)
+{
+    struct _variable *ptr;
+
+    ptr = calloc(1, sizeof *ptr);
+    if (!ptr) return NULL;
+
+    ptr->name = strdup("@");
+    ptr->value = strdup("");
+    if (!ptr->name || !ptr->value) {
+	free(ptr->name);
+	free(ptr->value);
+	free(ptr);
+	return NULL;
+    }
+    
+    return ptr;
+}
+
+
+
+const char * GetVariable(VariableSpace space, const char * name)
+{
+    struct _variable *current;
+
+    if (!space)
+	return NULL;
+
+    if (strspn(name, VALID_VARIABLE_CHARS) != strlen(name)) return NULL;
+
+    for (current = space; current; current = current->next) {
+#ifdef USE_ASSERT_CHECKING
+	assert(current->name);
+	assert(current->value);
+#endif
+	if (strcmp(current->name, name)==0)
+	    return current->value;
+    }
+
+    return NULL;
+}
+
+
+
+bool GetVariableBool(VariableSpace space, const char * name)
+{
+    return GetVariable(space, name)!=NULL ? true : false;
+}
+
+
+
+bool SetVariable(VariableSpace space, const char * name, const char * value)
+{
+    struct _variable *current, *previous;
+
+    if (!space)
+	return false;
+
+    if (!value)
+	return DeleteVariable(space, name);
+
+    if (strspn(name, VALID_VARIABLE_CHARS) != strlen(name)) return false;
+
+    for (current = space; current; previous = current, current = current->next) {
+#ifdef USE_ASSERT_CHECKING
+	assert(current->name);
+	assert(current->value);
+#endif
+	if (strcmp(current->name, name)==0) {
+	    free (current->value);
+	    current->value = strdup(value);
+	    return current->value ? true : false;
+	}
+    }
+
+    previous->next = calloc(1, sizeof *(previous->next));
+    if (!previous->next)
+	return false;
+    previous->next->name = strdup(name);
+    if (!previous->next->name)
+	return false;
+    previous->next->value = strdup(value);
+    return previous->next->value ? true : false;
+}
+
+
+
+bool DeleteVariable(VariableSpace space, const char * name)
+{
+    struct _variable *current, *previous;
+
+    if (!space)
+	return false;
+
+    if (strspn(name, VALID_VARIABLE_CHARS) != strlen(name)) return false;
+
+    for (current = space, previous = NULL; current; previous = current, current = current->next) {
+#ifdef USE_ASSERT_CHECKING
+	assert(current->name);
+	assert(current->value);
+#endif
+	if (strcmp(current->name, name)==0) {
+	    free (current->name);
+	    free (current->value);
+	    if (previous)
+		previous->next = current->next;
+	    free(current);
+	    return true;
+	}
+    }
+
+    return true;
+}
+
+
+
+void DestroyVariableSpace(VariableSpace space)
+{
+    if (!space)
+	return;
+
+    DestroyVariableSpace(space->next);
+    free(space);
+}