diff -r c2f4c0285180 -r f600b0d1fc5d bl/blstring.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bl/blstring.c	Fri Jan 27 10:30:16 2012 +0000
@@ -0,0 +1,90 @@
+#include <stdlib.h>
+#include <string.h>
+#include <bl/blstring.h>
+#include <bl/types.h>
+#include <bl/mem.h>
+#include <bl/strfuncs.h>
+
+/*
+ * Strings which manage their own memory
+ */
+
+String *string_new(const char *init)
+{
+    String *string=mem_new(String,1);
+    if (!init)
+	init="";
+    string->len=strlen(init);
+    string->alloc=string->len+1;
+    string->str=str_dup(init);
+    return string;
+}
+
+/*
+ * Free a string and either return the contents (if free_segment is FALSE)
+ * or free the contents as well and return NULL (if free_segment is TRUE).
+ */
+char *string_free(String *string,boolean free_segment)
+{
+    char *retval;
+    if (free_segment)
+    {
+	mem_free(string->str);
+	retval=NULL;
+    }
+    else
+	retval=string->str;
+    mem_free(string);
+    return retval;
+}
+
+/*
+ * Append a byte to string.
+ */
+void string_append_c(String *string,char c)
+{
+    if (string->len+1==string->alloc)
+    {
+	string->alloc*=2;
+	string->str=mem_renew(char,string->str,string->alloc);
+    }
+    string->str[string->len++]=c;
+    string->str[string->len]='\0';
+}
+
+/*
+ * Append len bytes from s to string. len may be passed as <0 if s is
+ * a nul-terminated string of unknown length.
+ */
+void string_append_len(String *string,const char *s,ssize_t len)
+{
+    if (len<0)
+	len=strlen(s);
+    if (string->len+len>=string->alloc)
+    {
+	while (string->len+len>=string->alloc)
+	    string->alloc*=2;
+	string->str=mem_renew(char,string->str,string->alloc);
+    }
+    memcpy(string->str+string->len,s,len);
+    string->len+=len;
+    string->str[string->len]='\0';
+}
+
+/*
+ * Sets the length of a String. If the length is less than the current length,
+ * the string will be truncated. If the length is greater than the current
+ * length, the contents of the newly added area are undefined. (However, as
+ * always, string->str[string->len] will be a nul byte.)
+ */
+void string_set_size(String *string,size_t len)
+{
+    if (len>=string->alloc)
+    {
+	while (len>=string->alloc)
+	    string->alloc*=2;
+	string->str=mem_renew(char,string->str,string->alloc);
+    }
+    string->len=len;
+    string->str[string->len]='\0';
+}