General Purpose Library Routines

Overview

This is collection of oddballs that didn’t fit anywhere else, and might move to more appropriate headers with the release of APR 1.0. More…

// typedefs

typedef struct apr_vformatter_buff_t apr_vformatter_buff_t;

// structs

struct apr_vformatter_buff_t;

// global functions

const char*
apr_filepath_name_get(const char* pathname);

int
apr_vformatter(
    int(*)(apr_vformatter_buff_t*b) flush_func,
    apr_vformatter_buff_t* c,
    const char* fmt,
    va_list ap
);

apr_status_t
apr_password_get(
    const char* prompt,
    char* pwbuf,
    apr_size_t* bufsize
);

// macros

#define HUGE_STRING_LEN

#define apr_killpg( \
    x, \
    y \
)

Detailed Documentation

This is collection of oddballs that didn’t fit anywhere else, and might move to more appropriate headers with the release of APR 1.0.

Typedefs

typedef struct apr_vformatter_buff_t apr_vformatter_buff_t

Global Functions

const char*
apr_filepath_name_get(const char* pathname)

return the final element of the pathname.. code-block:: none

For example:
“/foo/bar/gum” -> “gum” “/foo/bar/gum/” -> “” “gum” -> “gum” “bs\path\stuff” -> “stuff”

Parameters:

pathname

The path to get the final element of

Returns:

the final element of the path

int
apr_vformatter(
    int(*)(apr_vformatter_buff_t*b) flush_func,
    apr_vformatter_buff_t* c,
    const char* fmt,
    va_list ap
)

apr_vformatter() is a generic printf-style formatting routine with some extensions… code-block:: none

The extensions are:

%pA takes a struct in_addr *, and prints it as a.b.c.d

%pI takes an :ref:`apr_sockaddr_t <doxid-structapr__sockaddr__t>` * and prints it as a.b.c.d:port or
[ipv6-address]:port

%pT takes an apr_os_thread_t * and prints it in decimal
('0' is printed if !APR_HAS_THREADS)

%pt takes an apr_os_thread_t * and prints it in hexadecimal
('0' is printed if !APR_HAS_THREADS)

%pm takes an apr_status_t * and prints the appropriate error
string (from apr_strerror) corresponding to that error code.

%pp takes a void * and outputs it in hex

%pB takes a apr_uint32_t * as bytes and outputs it's apr_strfsize

%pF same as above, but takes a apr_off_t *

%pS same as above, but takes a apr_size_t *

%pA, %pI, %pT, %pp are available from APR 1.0.0 onwards (and in 0.9.x).
%pt is only available from APR 1.2.0 onwards.
%pm, %pB, %pF and %pS are only available from APR 1.3.0 onwards.

The %p hacks are to force gcc's printf warning code to skip
over a pointer argument without complaining.  This does
mean that the ANSI-style %p (output a void * in hex format) won't
work as expected at all, but that seems to be a fair trade-off
for the increased robustness of having printf-warnings work.

Additionally, apr_vformatter allows for arbitrary output methods
using the apr_vformatter_buff and flush_func.

The apr_vformatter_buff has two elements curpos and endpos.
curpos is where apr_vformatter will write the next byte of output.
It proceeds writing output to curpos, and updating curpos, until
either the end of output is reached, or curpos == endpos (i.e. the
buffer is full).

If the end of output is reached, apr_vformatter returns the
number of bytes written.

When the buffer is full, the flush_func is called.  The flush_func
can return -1 to indicate that no further output should be attempted,
and apr_vformatter will return immediately with -1.  Otherwise
the flush_func should flush the buffer in whatever manner is
appropriate, re apr_pool_t nitialize curpos and endpos, and return 0.

Note that flush_func is only invoked as a result of attempting to
write another byte at curpos when curpos >= endpos.  So for
example, it's possible when the output exactly matches the buffer
space available that curpos == endpos will be true when
apr_vformatter returns.

apr_vformatter does not call out to any other code, it is entirely
self-contained.  This allows the callers to do things which are
otherwise "unsafe".  For example, apr_psprintf uses the "scratch"
space at the unallocated end of a block, and doesn't actually
complete the allocation until apr_vformatter returns.  apr_psprintf
would be completely broken if apr_vformatter were to call anything
that used this same pool.  Similarly http_bprintf() uses the "scratch"
space at the end of its output buffer, and doesn't actually note
that the space is in use until it either has to flush the buffer
or until apr_vformatter returns.

Parameters:

flush_func	The function to call when the buffer is full
c	The buffer to write to
fmt	The format string
ap	The arguments to use to fill out the format string.

apr_status_t
apr_password_get(
    const char* prompt,
    char* pwbuf,
    apr_size_t* bufsize
)

Display a prompt and read in the password from stdin. If the password entered must be truncated to fit in the provided buffer, APR_ENAMETOOLONG will be returned. Note that the bufsize paramater is passed by reference for no reason; its value will never be modified by the apr_password_get() function.

Parameters:

prompt	The prompt to display
pwbuf	Buffer to store the password
bufsize	The length of the password buffer.

Macros

#define HUGE_STRING_LEN

A constant representing a ‘large’ string.

#define apr_killpg( \
    x, \
    y \
)

apr_killpg Small utility macros to make things easier to read. Not usually a goal, to be sure..