gistfile1.c

#include <Python.h>
#include <ctype.h>
#include <stdbool.h>

#define MAX_STRING_LENGTH 500
#define UPPER(c)   (((c)>='a'  && (c) <= 'z') ? ((c)+('A'-'a')) : (c) )

char* CAP(char *txt)
{
  *txt = UPPER(*txt);
  return txt;
}

static PyObject* cutils_format(PyObject *self, PyObject *args);

static PyMethodDef CutilsMethods[] = {
	{"format", cutils_format, METH_VARARGS,
	"Format string for output."},
	{NULL, NULL, 0, NULL}
};

static struct PyModuleDef cutils = {
	PyModuleDef_HEAD_INIT,
	"cutils",
	NULL,
	-1,
	CutilsMethods
};

static PyObject *FormatError;

PyMODINIT_FUNC PyInit_cutils(void) {
	PyObject *m;
	
	m = PyModule_Create(&cutils);
	if(!m)
		return NULL;
	FormatError = PyErr_NewException("cutils.format.error", NULL, NULL);
	Py_INCREF(FormatError);
	PyModule_AddObject(m, "error", FormatError);
	return m;
}

static PyObject* cutils_format(PyObject *self, PyObject *args) {
	char *str;
	PyObject *sender;

	if(!PyArg_ParseTuple(args, "sO", &str, &sender))
		return NULL;
	
	const char *i = NULL;
	char lbuf[MAX_STRING_LENGTH], *buf, *j;
	bool uppercasenext = false;

	buf = lbuf;

	while(1) {
		if (*str == '$') {
			switch (*(++str)) {
				case 'n':
                                        // obviously won't work
					i = PyObject_GetAttrString(sender, "__name");
					break;
				case 'u': // uppercase previous word
					for (j=buf; j > lbuf && !isspace((int) *(j-1)); j--);
					if (j != buf)
				 		*j = UPPER(*j);
					i = "";
					break;
				case 'U': // uppercase next word
					uppercasenext = true;
					i = "";
					break;
				case '$':
					i = "$";
					break;
				default:
					return PyErr_Format(FormatError, "Invalid code %c in format string", *str);
					i = "";
					break;
			} // switch
			while ((*buf = *(i++))) {
				if (uppercasenext && !isspace((int) *buf)) {
					*buf = UPPER(*buf);
					uppercasenext = false;
				}
				buf++;
			}
			str++;
		} 
		else if (!(*(buf++) = *(str++))) {
			break;
		} 
		else if (uppercasenext && !isspace((int) *(buf-1))) {
			*(buf-1) = UPPER(*(buf-1));
			uppercasenext = false;
		}
	}

	*(--buf) = '\r';
	*(++buf) = '\n';
	*(++buf) = '\0';

	return PyUnicode_FromString(CAP(lbuf));
}