diff options
| -rw-r--r-- | README.md | 29 | ||||
| -rw-r--r-- | lib.c | 94 | ||||
| -rw-r--r-- | tests/custom/03_stdlib/56_hexdec | 29 | ||||
| -rw-r--r-- | tests/custom/03_stdlib/57_hexenc | 24 |
4 files changed, 176 insertions, 0 deletions
@@ -1473,3 +1473,32 @@ does not implement this clock type. clock(); // [ 1647954926, 798269464 ] clock(true); // [ 474751, 527959975 ] ``` + +#### 6.70. `hexdec(hexstring[, skipchars])` + +The `hexdec()` function decodes the given hexadecimal digit string into +a byte string, optionally skipping specified characters. + +If the characters to skip are not specified, a default of `" \t\n"` is +used. + +Returns null if the input string contains invalid characters or an uneven +amount of hex digits. + +Returns the decoded byte string on success. + +```javascript +hexdec("48656c6c6f20776f726c64210a"); // "Hello world!\n" +hexdec("44:55:66:77:33:44", ":"); // "DUfw3D" +``` + +#### 6.71. `hexenc(val)` + +The `hexenc()` function encodes the given byte string into a hexadecimal +digit string, converting the input value to a string if needed. + +Returns the encoded hexadecimal digit string. + +```javascript +hexenc("Hello world!\n"); // "48656c6c6f20776f726c64210a" +``` @@ -3352,6 +3352,98 @@ uc_clock(uc_vm_t *vm, size_t nargs) return res; } +static uc_value_t * +uc_hexenc(uc_vm_t *vm, size_t nargs) +{ + const char *hex = "0123456789abcdef"; + uc_value_t *input = uc_fn_arg(0); + uc_stringbuf_t *buf; + size_t off, len; + uint8_t byte; + + if (!input) + return NULL; + + buf = ucv_stringbuf_new(); + off = printbuf_length(buf); + + ucv_to_stringbuf(vm, buf, input, false); + + len = printbuf_length(buf) - off; + + /* memset the last expected output char to grow the output buffer */ + printbuf_memset(buf, off + len * 2, 0, 1); + + /* translate string into hex back to front to reuse the same buffer */ + while (len > 0) { + byte = buf->buf[--len + off]; + buf->buf[off + len * 2 + 0] = hex[byte / 16]; + buf->buf[off + len * 2 + 1] = hex[byte % 16]; + } + + /* do not include sentinel `\0` in string length */ + buf->bpos--; + + return ucv_stringbuf_finish(buf); +} + +static inline uint8_t +hexval(unsigned char c, bool lo) +{ + return ((c > '9') ? (c - 'a') + 10 : c - '0') << (lo ? 0 : 4); +} + +static uc_value_t * +uc_hexdec(uc_vm_t *vm, size_t nargs) +{ + uc_value_t *input = uc_fn_arg(0); + uc_value_t *skip = uc_fn_arg(1); + size_t len, off, n, i; + uc_stringbuf_t *buf; + unsigned char *p; + const char *s; + + if (ucv_type(input) != UC_STRING) + return NULL; + + if (skip && ucv_type(skip) != UC_STRING) + return NULL; + + p = (unsigned char *)ucv_string_get(input); + len = ucv_string_length(input); + + s = skip ? (const char *)ucv_string_get(skip) : " \t\n"; + + for (i = 0, n = 0; i < len; i++) { + if (isxdigit(p[i])) + n++; + else if (!s || !strchr(s, p[i])) + return NULL; + } + + if (n & 1) + return NULL; + + buf = ucv_stringbuf_new(); + off = printbuf_length(buf); + + /* preallocate the output buffer */ + printbuf_memset(buf, off, 0, n / 2 + 1); + + for (i = 0, n = 0; i < len; i++) { + if (!isxdigit(p[i])) + continue; + + buf->buf[off + (n >> 1)] |= hexval(p[i] | 32, n & 1); + n++; + } + + /* do not include sentinel `\0` in string length */ + buf->bpos--; + + return ucv_stringbuf_finish(buf); +} + const uc_function_list_t uc_stdlib_functions[] = { { "chr", uc_chr }, @@ -3417,6 +3509,8 @@ const uc_function_list_t uc_stdlib_functions[] = { { "timelocal", uc_timelocal }, { "timegm", uc_timegm }, { "clock", uc_clock }, + { "hexdec", uc_hexdec }, + { "hexenc", uc_hexenc }, }; diff --git a/tests/custom/03_stdlib/56_hexdec b/tests/custom/03_stdlib/56_hexdec new file mode 100644 index 0000000..cb842ca --- /dev/null +++ b/tests/custom/03_stdlib/56_hexdec @@ -0,0 +1,29 @@ +The `hexdec()` function decodes the given hexadecimal digit string into +a byte string, optionally skipping specified characters. + +Returns null if the input string contains invalid characters or an uneven +amount of hex digits. + +Returns the decoded byte string on success. + +-- Testcase -- +{% + printf("%.J\n", [ + hexdec("44 55 66 77 33 44\n"), // whitespace is skipped by default + hexdec("44-55-66:77-33-44", ":-"), // skip specified characters + hexdec("abc"), // error; uneven amount of digits + hexdec("ab cd !"), // error; non-whitespace, non-hex, non-skipped char + hexdec(1234), // error; non-string input + ]); +%} +-- End -- + +-- Expect stdout -- +[ + "DUfw3D", + "DUfw3D", + null, + null, + null +] +-- End -- diff --git a/tests/custom/03_stdlib/57_hexenc b/tests/custom/03_stdlib/57_hexenc new file mode 100644 index 0000000..235ad66 --- /dev/null +++ b/tests/custom/03_stdlib/57_hexenc @@ -0,0 +1,24 @@ +The `hexenc()` function encodes the given byte string into a hexadecimal +digit string, converting the input value to a string if needed. + +Returns the encoded hexadecimal digit string. + +-- Testcase -- +{% + printf("%.J\n", [ + hexenc("Hello world!\n"), // encoding a simple string + hexenc(""), // empty input -> empty output + hexenc([1, 2, 3]), // implicit stringification + hexenc(null), // null input -> null output + ]); +%} +-- End -- + +-- Expect stdout -- +[ + "48656c6c6f20776f726c64210a", + "", + "5b20312c20322c2033205d", + null +] +-- End -- |