#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <ctype.h>

#include "mangle.h"

#include "c.h"

#define isoctal(a) (((a) & ~7) == '0')

#define from_hex(c) (isdigit(c) ? c - '0' : tolower(c) - 'a' + 10)

static inline int is_unwanted_char(unsigned char c)

{

return c <= 0x20 || c == 0x7f || c == '\\';

}

char *mangle(const char *s)

{

char *ss, *sp;

if (!s)

return NULL;

ss = sp = malloc(4 * strlen(s) + 1);

if (!sp)

return NULL;

while(1) {

if (!*s) {

*sp = '\0';

break;

}

if (is_unwanted_char(*s)) {

*sp++ = '\\';

*sp++ = '0' + ((*s & 0300) >> 6);

*sp++ = '0' + ((*s & 070) >> 3);

*sp++ = '0' + (*s & 07);

} else

*sp++ = *s;

s++;

}

return ss;

}

void unmangle_to_buffer(const char *s, char *buf, size_t len)

{

size_t sz = 0;

if (!s)

return;

while(*s && sz < len - 1) {

if (*s == '\\' && sz + 3 < len - 1 && isoctal(s[1]) &&

isoctal(s[2]) && isoctal(s[3])) {

*buf++ = 64*(s[1] & 7) + 8*(s[2] & 7) + (s[3] & 7);

s += 4;

sz += 4;

} else {

*buf++ = *s++;

sz++;

}

}

*buf = '\0';

}

size_t unhexmangle_to_buffer(const char *s, char *buf, size_t len)

{

size_t sz = 0;

const char *buf0 = buf;

if (!s)

return 0;

while(*s && sz < len - 1) {

if (*s == '\\' && sz + 3 < len - 1 && s[1] == 'x' &&

isxdigit(s[2]) && isxdigit(s[3])) {

*buf++ = from_hex(s[2]) << 4 | from_hex(s[3]);

s += 4;

sz += 4;

} else {

*buf++ = *s++;

sz++;

}

}

*buf = '\0';

return buf - buf0 + 1;

}

size_t unescape_to_buffer(const char *s, const char *wanted, char *buf, size_t len)

{

size_t sz = 0;

const char *buf0 = buf;

while (*s && sz < len - 1) {

if (*s == '\\' && sz + 1 < len - 1 && strchr(wanted, s[1])) {

*buf++ = s[1];

s += 2;

sz += 2;

} else {

*buf++ = *s++;

sz++;

}

}

*buf = '\0';

return buf - buf0 + 1;

}

static inline const char *skip_nonspaces(const char *s)

{

while (s && *s && !(*s == ' ' || *s == '\t'))

s++;

return s;

}

char *unmangle(const char *s, const char **end)

{

char *buf;

const char *e;

size_t sz;

if (!s)

return NULL;

e = skip_nonspaces(s);

sz = e - s + 1;

if (end)

*end = e;

if (e == s)

return NULL; /* empty string */

buf = malloc(sz);

if (!buf)

return NULL;

unmangle_to_buffer(s, buf, sz);

return buf;

}

#ifdef TEST_PROGRAM_MANGLE

#include <errno.h>

int main(int argc, char *argv[])

{

char *p = NULL;

if (argc < 3) {

fprintf(stderr, "usage: %s --mangle|unmangle|unescape <string>\n",

program_invocation_short_name);

return EXIT_FAILURE;

}

if (!strcmp(argv[1], "--mangle")) {

p = mangle(argv[2]);

printf("mangled: '%s'\n", p);

free(p);

}

else if (!strcmp(argv[1], "--unmangle")) {

char *x = unmangle(argv[2], NULL);

if (x) {

printf("unmangled: '%s'\n", x);

free(x);

}

x = strdup(argv[2]);

if (x) {

unmangle_to_buffer(x, x, strlen(x) + 1);

printf("self-unmangled: '%s'\n", x);

free(x);

}

}

else if (!strcmp(argv[1], "--unescape")) {

char *x = strdup(argv[2]);

if (x) {

unescape_to_buffer(x, ",\"", x, strlen(x) + 1);

printf("self-unescaped: '%s'\n", x);

free(x);

}

}

return EXIT_SUCCESS;

}

#endif /* TEST_PROGRAM_MANGLE */