append_format

append_format - Append a separator and formatted data to a string in C

int append_flags_sep_format(char **str, int flags, const char *sep,
                            const char *format, ...);

Example:

  char *str = (char *)strdup("foo");
  if(str) {
    if(append_flags_sep_format(&str, 0, "; ", "%d %s", 123, "abc") >= 0) {
      printf("%s\n", str); /* prints "foo; 123 abc" */
    }
  }

In addition to the function above, there are several function-like macros that wrap it. For illustrative purposes here are those macros as prototypes:

/* same as append_flags_sep_format but no flags or separator */
int append_format(char **str, const char *format, ...);

/* same as append_flags_sep_format but no flags */
int append_sep_format(char **str, const char *sep, const char *format, ...);

/* same as append_sep_format but remove all trailing CR and LF from *str before
   and after appending to it */
int append_rmCRLFs_sep_format(char **str, const char *sep,
                              const char *format, ...);
                              
/* same as append_format but remove all trailing CR and LF from *str before and
   after appending to it */
int append_rmCRLFs_format(char **str, const char *format, ...);

append_format.{c,h} can be included in any C or C++ project.

Flags

AF_REMOVE_CR_LF_BEFORE_APPEND

Remove all trailing CR and LF from *str BEFORE appending to it.

AF_REMOVE_CR_LF_AFTER_APPEND

Remove all trailing CR and LF from *str AFTER appending to it.

AF_REMOVE_CR_LF_BEFORE_AND_AFTER_APPEND

Both of the above: Remove all trailing CR and LF from *str BEFORE and AFTER appending to it.

AF_APPEND_SEP_IF_STR_EMPTY

Append the separator even if *str before append is NULL or empty "".

AF_APPEND_SEP_IF_FORMAT_EMPTY

Append the separator even if the format outcome to append is empty "".

AF_APPEND_SEP_ALWAYS

Both of the above: Append the separator even if *str is NULL or empty "" OR the format outcome to append is empty "".

AF_ALL_FLAGS

All flags. This value will change as flags are added.

Documentation

Full documentation is in the comment block above append_flags_sep_format in append_format.c.

Other

Testing

test_append_format is a Visual Studio solution that will test various permutations of append_format. If a test fails two cpu beeps (\a\a) are sent and then an attempt is made to break (or abort if that's not possible).

License

append_format is licensed under the FreeBSD license which is also referred to as the 2-clause BSD license or simplified BSD license. It is a non-restrictive GPL-compatible free software license. It is similar to the MIT license and is closed source permissive.

test_append_format is under the same FreeBSD license unless otherwise stated. Currently there is only one exception, the 'dump' function is from libcurl which uses an MIT/X derivate license.

You may not remove my copyright or the copyright of any contributors under the terms of either license. For full license terms please review LICENSE.txt.

Source

The source can be found on GitHub. Since you're reading this maybe you're already there?

Send me any questions you have

Jay Satiro <raysatiro$at$yahoo{}com> and put append_format in the subject.