Util function to convert string charset.

src/util.c

@@ -17,6 +17,7 @@
 #include <errno.h>
 #include <ctype.h>
 #include <stdio.h>
+#include <limits.h>
 
 int int_pow(int base, int power)
 {
@@ -27,6 +28,45 @@ int int_pow(int base, int power)
     return result;
 }
 
+
+int strconv(const char *str, const char *icharset, const char *ocharset,
+            char **output)
+{
+    size_t inbytes;
+    size_t outbytes;
+    size_t n;
+    iconv_t conv;
+    char *out;
+    char *src;
+    char *ret;
+
+    inbytes = strlen(str);
+    outbytes = (inbytes + 1) * MB_LEN_MAX;
+    out = malloc(outbytes);
+    if (out == NULL) {
+        return ISO_MEM_ERROR;
+    }
+
+    conv = iconv_open(ocharset, icharset);
+    if (conv == (iconv_t)(-1)) {
+        return ISO_CHARSET_CONV_ERROR;
+    }
+    src = (char *)str;
+    ret = (char *)out;
+
+    n = iconv(conv, &src, &inbytes, &ret, &outbytes);
+    if (n == -1) {
+        /* error */
+        iconv_close(conv);
+        return ISO_CHARSET_CONV_ERROR;
+    }
+    iconv_close(conv);
+    *ret = '\0';
+
+    *output = realloc(out, ret - out);
+    return ISO_SUCCESS;
+}
+
 /**
  * Convert a str in a specified codeset to WCHAR_T. 
  * The result must be free() when no more needed

src/util.h

@@ -32,6 +32,23 @@ extern inline int round_up(unsigned int n, unsigned int mul)
 
 int int_pow(int base, int power);
 
+/**
+ * Convert the charset encoding of a given string.
+ * 
+ * @param input
+ *      Input string
+ * @param icharset
+ *      Input charset. Must be supported by iconv
+ * @param ocharset
+ *      Output charset. Must be supported by iconv
+ * @param output
+ *      Location where the pointer to the ouput string will be stored
+ * @return
+ *      1 on success, < 0 on error
+ */
+int strconv(const char *input, const char *icharset, const char *ocharset,
+            char **output);
+
 /**
  * Convert a given string from any input charset to ASCII
  * 
@@ -39,7 +56,7 @@ int int_pow(int base, int power);
  *      Input charset. Must be supported by iconv
  * @param input
  *      Input string
- * @param ouput
+ * @param output
  *      Location where the pointer to the ouput string will be stored
  * @return
  *      1 on success, < 0 on error

test/test_util.c

@@ -5,8 +5,46 @@
  */
 #include "test.h"
 #include "util.h"
+#include "error.h"
 
 #include <string.h>
+#include <stdlib.h>
+
+static void test_strconv()
+{
+    int ret;
+    char *out;
+    
+    /* Prova de cadeia com codificação ISO-8859-15 */
+    unsigned char in1[45] = 
+         {0x50, 0x72, 0x6f, 0x76, 0x61, 0x20, 0x64, 0x65, 0x20, 0x63, 0x61, 
+          0x64, 0x65, 0x69, 0x61, 0x20, 0x63, 0x6f, 0x6d, 0x20, 0x63, 0x6f, 
+          0x64, 0x69, 0x66, 0x69, 0x63, 0x61, 0xe7, 0xe3, 0x6f, 0x20, 0x49, 
+          0x53, 0x4f, 0x2d, 0x38, 0x38, 0x35, 0x39, 0x2d, 0x31, 0x35, 0x0a, 
+          0x00}; /* encoded in ISO-8859-15 */
+    unsigned char out1[47] = 
+         {0x50, 0x72, 0x6f, 0x76, 0x61, 0x20, 0x64, 0x65, 0x20, 0x63, 0x61, 
+          0x64, 0x65, 0x69, 0x61, 0x20, 0x63, 0x6f, 0x6d, 0x20, 0x63, 0x6f, 
+          0x64, 0x69, 0x66, 0x69, 0x63, 0x61, 0xc3, 0xa7, 0xc3, 0xa3, 0x6f, 
+          0x20, 0x49, 0x53, 0x4f, 0x2d, 0x38, 0x38, 0x35, 0x39, 0x2d, 0x31, 
+          0x35, 0x0a, 0x00}; /* encoded in UTF-8 */
+    unsigned char in2[45] = 
+         {0x50, 0x72, 0x6f, 0x76, 0x61, 0x20, 0x64, 0x65, 0x20, 0x63, 0x61, 
+          0x64, 0x65, 0x69, 0x61, 0x20, 0x63, 0x6f, 0x6d, 0x20, 0x63, 0x6f, 
+          0x64, 0x69, 0x66, 0x69, 0x63, 0x61, 0xe7, 0xe3, 0x6f, 0x20, 0x49, 
+          0x53, 0x4f, 0x2d, 0x38, 0x38, 0xff, 0xff, 0x2d, 0x31, 0x35, 0x0a, 
+          0x00}; /* incorrect encoding */
+    
+    /* ISO-8859-15 to UTF-8 */
+    ret = strconv((char*)in1, "ISO-8859-15", "UTF-8", &out);
+    CU_ASSERT_EQUAL(ret, 1);
+    CU_ASSERT_STRING_EQUAL(out, (char*)out1);
+    free(out);
+    
+    /* try with an incorrect input */
+    ret = strconv((char*)in2, "UTF-8", "ISO-8859-15", &out);
+    CU_ASSERT_EQUAL(ret, ISO_CHARSET_CONV_ERROR);
+}
 
 static void test_div_up()
 {
@@ -260,6 +298,7 @@ void add_util_suite()
 {
     CU_pSuite pSuite = CU_add_suite("UtilSuite", NULL, NULL);
 
+    CU_add_test(pSuite, "strconv()", test_strconv);
     CU_add_test(pSuite, "div_up()", test_div_up);
     CU_add_test(pSuite, "round_up()", test_round_up);
     CU_add_test(pSuite, "iso_bb()", test_iso_bb);