+/* -*-c-*-
+ *
+ * $Id: url.c,v 1.1 1999/06/01 09:49:48 mdw Exp $
+ *
+ * Parsing and construction of url-encoded name/value pairs
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: url.c,v $
+ * Revision 1.1 1999/06/01 09:49:48 mdw
+ * New files for url-encoding and decoding.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "dstr.h"
+#include "url.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @url_initenc@ --- *
+ *
+ * Arguments: @url_ectx *ctx@ = pointer to context block
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a URL encoding context.
+ */
+
+void url_initenc(url_ectx *ctx)
+{
+ ctx->f = 0;
+}
+
+/* --- @encode@ --- *
+ *
+ * Arguments: @dstr *d@ = pointer to output string
+ * @const char *p@ = pointer to thing to encode
+ *
+ * Returns: ---
+ *
+ * Use: Encodes the input string into the output string.
+ */
+
+static void encode(dstr *d, const char *p)
+{
+ while (*p) {
+ switch (*p) {
+ case ' ':
+ DPUTC(d, '+');
+ break;
+ default:
+ if (*p >= 33 && *p < 127)
+ DPUTC(d, *p);
+ else
+ case '&':
+ case '+':
+ case '=':
+ case '%':
+ dstr_putf(d, "%%%02x", *p);
+ break;
+ }
+ p++;
+ }
+}
+
+/* --- @url_enc@ --- *
+ *
+ * Arguments: @url_ectx *ctx@ = pointer to encoding context
+ * @dstr *d@ = pointer to output string
+ * @const char *name@ = pointer to name
+ * @const char *value@ = pointer to value
+ *
+ * Returns: ---
+ *
+ * Use: Writes an assignment between @name@ and @value@ to the
+ * output string, encoding the values properly.
+ */
+
+void url_enc(url_ectx *ctx, dstr *d, const char *name, const char *value)
+{
+ if (ctx->f & URLF_SEP)
+ DPUTC(d, '&');
+ encode(d, name);
+ DPUTC(d, '=');
+ encode(d, value);
+ DPUTZ(d);
+ ctx->f |= URLF_SEP;
+}
+
+/* --- @url_initdec@ --- *
+ *
+ * Arguments: @url_dctx *ctx@ = pointer to context block
+ * @const char *p@ = string to read data from
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a URL decoding context.
+ */
+
+void url_initdec(url_dctx *ctx, const char *p)
+{
+ ctx->p = p;
+}
+
+/* --- @decode@ --- *
+ *
+ * Arguments: @dstr *d@ = pointer to output string
+ * @const char *p@ = pointer to input data
+ * @int eq@ = whether to stop at `=' characters
+ *
+ * Returns: Pointer to next available character.
+ *
+ * Use: Does a URL decode.
+ */
+
+static const char *decode(dstr *d, const char *p, int eq)
+{
+ if (!*p)
+ return (0);
+ for (;;) {
+ switch (*p) {
+ case '=':
+ if (eq)
+ return (p);
+ DPUTC(d, *p);
+ break;
+ case 0:
+ case '&':
+ return (p);
+ case '+':
+ DPUTC(d, ' ');
+ break;
+ case '%': {
+ unsigned int ch;
+ int n;
+ int x = sscanf(p + 1, "%2x%n", &ch, &n);
+ if (x == 1) {
+ DPUTC(d, ch);
+ p += n;
+ break;
+ }
+ }
+ default:
+ DPUTC(d, *p);
+ break;
+ }
+ p++;
+ }
+}
+
+/* --- @url_dec@ --- *
+ *
+ * Arguments: @url_dctx *ctx@ = pointer to decode context
+ * @dstr *n@ = pointer to output string for name
+ * @dstr *v@ = pointer to output string for value
+ *
+ * Returns: Nonzero if it read something, zero if there's nothing left
+ *
+ * Use: Decodes the next name/value pair from a urlencoded string.
+ */
+
+int url_dec(url_dctx *ctx, dstr *n, dstr *v)
+{
+ const char *p = ctx->p;
+ size_t l = n->len;
+
+again:
+ if ((p = decode(n, p, 1)) == 0 || *p == 0)
+ return (0);
+ if (*p != '=') {
+ p++;
+ n->len = l;
+ goto again;
+ }
+ p++;
+ if ((p = decode(v, p, 0)) == 0)
+ return (0);
+ DPUTZ(n);
+ DPUTZ(v);
+ ctx->p = p;
+ return (1);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
~mdw / mLib / commitdiff