Infrastructure: Split the files into subdirectories.

[mLib] / codec / url.c

diff --git a/codec/url.c b/codec/url.c
new file mode 100644 (file)
index 0000000..f502f7c
--- /dev/null
+++ b/codec/url.c
@@ -0,0 +1,217 @@
+/* -*-c-*-
+ *
+ * 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.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <ctype.h>
+#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:  @url_ectx *ctx@ = encoding context
+ *             @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(url_ectx *ctx, dstr *d, const char *p)
+{
+  while (*p) {
+    switch (*p) {
+      case ' ':
+       DPUTC(d, '+');
+       break;
+      default:
+       if ((ctx->f & URLF_LAX) || isalnum((unsigned char)*p))
+         goto safe;
+       else
+         goto unsafe;
+      case '/':
+      case '~':
+       if (ctx->f & URLF_STRICT)
+         goto unsafe;
+      case '-':
+      case '.':
+      case '_':
+      safe:
+       DPUTC(d, *p);
+       break;
+      unsafe:
+      case '+':
+      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, (ctx->f & URLF_SEMI) ? ';' : '&');
+  encode(ctx, d, name);
+  DPUTC(d, '=');
+  encode(ctx, 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; ctx->f = 0; }
+
+/* --- @decode@ --- *
+ *
+ * Arguments:  @url_dctx *ctx@ = pointer to the context
+ *             @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(url_dctx *ctx, dstr *d, const char *p, int eq)
+{
+  if (!*p)
+    return (0);
+  for (;;) {
+    switch (*p) {
+      case '=':
+       if (eq)
+         return (p);
+       goto boring;
+      case ';':
+       if (ctx->f & URLF_SEMI)
+         return (p);
+       goto boring;
+      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:
+      boring:
+       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(ctx, n, p, 1)) == 0 || *p == 0)
+    return (0);
+  if (*p != '=') {
+    p++;
+    n->len = l;
+    goto again;
+  }
+  p++;
+  if ((p = decode(ctx, v, p, 0)) == 0)
+    return (0);
+  DPUTZ(n);
+  DPUTZ(v);
+  ctx->p = p;
+  return (1);
+}
+
+/*----- That's all, folks -------------------------------------------------*/