string my_test_function(string str,int n)

./ext_skel --extname=extend_test --proto=extend_test.def

PHP_ARG_ENABLE(extend_test, whether to enable extend_test support,

Make sure that the comment is aligned:

[  --enable-extend_test           Enable extend_test support])

PHP_FUNCTION(my_test_function)

{

    char *str = NULL;

    int argc = ZEND_NUM_ARGS();

    size_t str_len;

    zend_long n;

    char *result;

    char *ptr;

    zend_long result_length;

    if (zend_parse_parameters(argc TSRMLS_CC, "sl", &str, &str_len, &n) == FAILURE)

        return;

    result_length = str_len * n;

    result = (char *) emalloc(result_length + 1);

    ptr = result;

    while (n--) {

        memcpy(ptr, str, str_len);

        ptr += str_len;

    }

    *ptr = '\0';

    RETURN_STRINGL(result, result_length);

}

make            

make install

extension=extend_test.so

<?php

echo my_test_function('a',5);