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# Strings

All text strings in MuPDF use the `UTF-8` encoding.

## Unicode

The following functions encode and decode `UTF-8` characters, and return the number of bytes used by the `UTF-8` character (at most `FZ_UTFMAX`).

    int fz_chartorune(int *rune, const char *str);
    int fz_runetochar(char *str, int rune);

## Locale Independent

Since many of the C string functions are locale dependent, we also provide our own locale independent versions of these functions. We also have a couple of semi-standard functions like `strsep` and `strlcpy` that we can’t rely on the system providing. These should be pretty self explanatory:

    char *fz_strdup(fz_context *ctx, const char *s);
    float fz_strtof(const char *s, char **es);
    char *fz_strsep(char **stringp, const char *delim);
    size_t fz_strlcpy(char *dst, const char *src, size_t n);
    size_t fz_strlcat(char *dst, const char *src, size_t n);
    void *fz_memmem(const void *haystack, size_t haystacklen, const void *needle, size_t needlelen);
    int fz_strcasecmp(const char *a, const char *b);

There are also a couple of functions to process filenames and URLs:

`char *fz_cleanname(char *path);`

  Rewrite path in-place to the shortest string that names the same path. Eliminates multiple and trailing slashes, and interprets “.” and “…”.

`void fz_dirname(char *dir, const char *path, size_t dir_size);`

  Extract the directory component from a path.

`char *fz_urldecode(char *url);`

  Decode URL escapes in-place.

## Formatting

Our `printf` family handles the common `printf` formatting characters, with a few minor differences. We also support several non-standard formatting characters. The same `printf` syntax is used in the `printf` functions in the I/O module as well.

    size_t fz_vsnprintf(char *buffer, size_t space, const char *fmt, va_list args);
    size_t fz_snprintf(char *buffer, size_t space, const char *fmt, ...);
    char *fz_asprintf(fz_context *ctx, const char *fmt, ...);

`%%`, `%c`, `%e`, `%f`, `%p`, `%x`, `%d`, `%u`, `%s`

  These behave as usual, but only take padding (+,0,space), width, and precision arguments.

`%g float`

  Prints the `float` in the shortest possible format that won’t lose precision, except `NaN` to `0`, `+Inf` to `FLT_MAX`, `-Inf` to `-FLT_MAX`.

`%M fz_matrix*`

  Prints all 6 coefficients in the matrix as `%g` separated by spaces.

`%R fz_rect*`

  Prints all `x0`, `y0`, `x1`, `y1` in the rectangle as `%g` separated by spaces.

`%P fz_point*`

  Prints `x`, `y` in the point as `%g` separated by spaces.

`%C int`

  Formats character as `UTF-8`. Useful to print unicode text.

`%q char*`

  Formats string using double quotes and C escapes.

`%( char*`

  Formats string using parenthesis quotes and Postscript escapes.

`%n char*`

  Formats string using prefix `/` and PDF name hex-escapes.