cgic.c

一般的UNIX系统都支持ANSI C,增加相应的库函数(和相应的h文件)就可以实现CGI,用于CGI编程的ANSI C库

	}
	if (!cgiWriteString(out, cgiPathInfo)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiPathTranslated)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiScriptName)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiQueryString)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiRemoteHost)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiRemoteAddr)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiAuthType)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiRemoteUser)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiRemoteIdent)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiContentType)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiAccept)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiUserAgent)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiReferrer)) {
		goto error;
	}
	if (!cgiWriteString(out, cgiCookie)) {
		goto error;
	}
	if (!cgiWriteInt(out, cgiContentLength)) {
		goto error;
	}
	e = cgiFormEntryFirst;
	while (e) {
		cgiFilePtr fp;
		if (!cgiWriteString(out, e->attr)) {
			goto error;
		}
		if (!cgiWriteString(out, e->value)) {
			goto error;
		}
		/* New 2.0 fields and file uploads */
		if (!cgiWriteString(out, e->fileName)) {
			goto error;
		}
		if (!cgiWriteString(out, e->contentType)) {
			goto error;
		}
		if (!cgiWriteInt(out, e->valueLength)) {
			goto error;
		}
		if (cgiFormFileOpen(e->attr, &fp) == cgiFormSuccess) {
			char buffer[1024];
			int got;
			if (!cgiWriteInt(out, 1)) {
				cgiFormFileClose(fp);
				goto error;
			}
			while (cgiFormFileRead(fp, buffer, 
				sizeof(buffer), &got) == cgiFormSuccess)
			{
				if (((int) fwrite(buffer, 1, got, out)) != got) {
					cgiFormFileClose(fp);
					goto error;
				}
			}
			if (cgiFormFileClose(fp) != cgiFormSuccess) {
				goto error;
			}
		} else {
			if (!cgiWriteInt(out, 0)) {
				goto error;
			}
		}
		e = e->next;
	}
	fclose(out);
	return cgiEnvironmentSuccess;
error:
	fclose(out);
	/* If this function is not defined in your system,
		you must substitute the appropriate 
		file-deletion function. */
	unlink(filename);
	return cgiEnvironmentIO;
}

static int cgiWriteString(FILE *out, char *s) {
	int len = (int) strlen(s);
	cgiWriteInt(out, len);
	if (((int) fwrite(s, 1, len, out)) != len) {
		return 0;
	}
	return 1;
}

static int cgiWriteInt(FILE *out, int i) {
	if (!fwrite(&i, sizeof(int), 1, out)) {
		return 0;
	}
	return 1;
}

static int cgiReadString(FILE *out, char **s);

static int cgiReadInt(FILE *out, int *i);

cgiEnvironmentResultType cgiReadEnvironment(char *filename) {
	FILE *in;
	cgiFormEntry *e = 0, *p;
	char *version;
	cgiEnvironmentResultType result;
	/* Free any existing data first */
	cgiFreeResources();
	/* Be sure to open in binary mode */
	in = fopen(filename, "rb");
	if (!in) {
		/* Can't access file */
		return cgiEnvironmentIO;
	}
	if (!cgiReadString(in, &version)) {
		goto error;
	}
	if (strcmp(version, "CGIC" CGIC_VERSION)) {
		/* 2.02: Merezko Oleg */
		free(version);
		return cgiEnvironmentWrongVersion;
	}	
	/* 2.02: Merezko Oleg */
	free(version);
	if (!cgiReadString(in, &cgiServerSoftware)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiServerName)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiGatewayInterface)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiServerProtocol)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiServerPort)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiRequestMethod)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiPathInfo)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiPathTranslated)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiScriptName)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiQueryString)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiRemoteHost)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiRemoteAddr)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiAuthType)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiRemoteUser)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiRemoteIdent)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiContentType)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiAccept)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiUserAgent)) {
		goto error;
	}
	if (!cgiReadString(in, &cgiReferrer)) {
		goto error;
	}
	/* 2.0 */
	if (!cgiReadString(in, &cgiCookie)) {
		goto error;
	}
	if (!cgiReadInt(in, &cgiContentLength)) {
		goto error;
	}
	p = 0;
	while (1) {
		int fileFlag;
		e = (cgiFormEntry *) calloc(1, sizeof(cgiFormEntry));
		if (!e) {
			cgiFreeResources();
			fclose(in);
			return cgiEnvironmentMemory;
		}
		memset(e, 0, sizeof(cgiFormEntry));
		if (!cgiReadString(in, &e->attr)) {
			/* This means we've reached the end of the list. */
			/* 2.02: thanks to Merezko Oleg */
			free(e);
			break;
		}
		if (!cgiReadString(in, &e->value)) {
			goto outOfMemory;
		}
		if (!cgiReadString(in, &e->fileName)) {
			goto outOfMemory;
		}
		if (!cgiReadString(in, &e->contentType)) {
			goto outOfMemory;
		}
		if (!cgiReadInt(in, &e->valueLength)) {
			goto outOfMemory;
		}
		if (!cgiReadInt(in, &fileFlag)) {
			goto outOfMemory;
		}
		if (fileFlag) {
			char buffer[1024];
			FILE *out;
			char tfileName[1024];
			int got;
			int len = e->valueLength;
			if (getTempFileName(tfileName)
				!= cgiParseSuccess)
			{
				result = cgiEnvironmentIO;
				goto error;
			}
			out = fopen(tfileName, "w+b");
			if (!out) {
				result = cgiEnvironmentIO;
				goto error;
			}
			while (len > 0) {		
				/* 2.01: try is a bad variable name in
					C++, and it wasn't being used
					properly either */
				int tryr = len;
				if (tryr > ((int) sizeof(buffer))) {
					tryr = sizeof(buffer);
				}
				got = fread(buffer, 1, tryr, in);
				if (got <= 0) {
					result = cgiEnvironmentIO;
					fclose(out);
					unlink(tfileName);
					goto error;
				}
				if (((int) fwrite(buffer, 1, got, out)) != got) {
					result = cgiEnvironmentIO;
					fclose(out);
					unlink(tfileName);
					goto error;
				}
				len -= got;
			}
			rewind(out);
			e->tfileName = (char *) malloc((int) strlen(tfileName) + 1);
			if (!e->tfileName) {
				result = cgiEnvironmentMemory;
				unlink(tfileName);
				goto error;
			}
			strcpy(e->tfileName, tfileName);
		} else {
			e->tfileName = (char *) malloc(1);
			if (!e->tfileName) {
				result = cgiEnvironmentMemory;
				goto error;
			}
		}	
		e->next = 0;
		if (p) {
			p->next = e;
		} else {
			cgiFormEntryFirst = e;
		}	
		p = e;
	}
	fclose(in);
	cgiRestored = 1;
	return cgiEnvironmentSuccess;
outOfMemory:
	result = cgiEnvironmentMemory;
error:
	cgiFreeResources();
	fclose(in);
	if (e) {
		if (e->attr) {
			free(e->attr);
		}
		if (e->value) {
			free(e->value);
		}
		if (e->fileName) {
			free(e->fileName);
		}
		if (e->contentType) {
			free(e->contentType);
		}
		if (e->tfileName) {
			free(e->tfileName);
		}
		free(e);
	}
	return result;
}

static int cgiReadString(FILE *in, char **s) {
	int len;
	/* 2.0 fix: test cgiReadInt for failure! */ 
	if (!cgiReadInt(in, &len)) {
		return 0;
	}
	*s = (char *) malloc(len + 1);
	if (!(*s)) {
		return 0;
	}	
	if (((int) fread(*s, 1, len, in)) != len) {
		return 0;
	}
	(*s)[len] = '\0';
	return 1;
}

static int cgiReadInt(FILE *out, int *i) {
	if (!fread(i, sizeof(int), 1, out)) {
		return 0;
	}
	return 1;
}

static int cgiStrEqNc(char *s1, char *s2) {
	while(1) {
		if (!(*s1)) {
			if (!(*s2)) {
				return 1;
			} else {
				return 0;
			}
		} else if (!(*s2)) {
			return 0;
		}
		if (isalpha(*s1)) {
			if (tolower(*s1) != tolower(*s2)) {
				return 0;
			}
		} else if ((*s1) != (*s2)) {
			return 0;
		}
		s1++;
		s2++;
	}
}

static int cgiStrBeginsNc(char *s1, char *s2) {
	while(1) {
		if (!(*s2)) {
			return 1;
		} else if (!(*s1)) {
			return 0;
		}
		if (isalpha(*s1)) {
			if (tolower(*s1) != tolower(*s2)) {
				return 0;
			}
		} else if ((*s1) != (*s2)) {
			return 0;
		}
		s1++;
		s2++;
	}
}

static char *cgiFindTarget = 0;
static cgiFormEntry *cgiFindPos = 0;

static cgiFormEntry *cgiFormEntryFindFirst(char *name) {
	cgiFindTarget = name;
	cgiFindPos = cgiFormEntryFirst;
	return cgiFormEntryFindNext();
}

static cgiFormEntry *cgiFormEntryFindNext() {
	while (cgiFindPos) {
		cgiFormEntry *c = cgiFindPos;
		cgiFindPos = c->next;
		if (!strcmp(c -> attr, cgiFindTarget)) {
			return c;
		}
	}
	return 0;
}

static int cgiFirstNonspaceChar(char *s) {
	int len = strspn(s, " \n\r\t");
	return s[len];
}

void cgiStringArrayFree(char **stringArray) {
	char *p;
	char **arrayItself = stringArray;
	p = *stringArray;
	while (p) {
		free(p);
		stringArray++;
		p = *stringArray;
	}
	/* 2.0: free the array itself! */
	free(arrayItself);
}	

cgiFormResultType cgiCookies(char ***result) {
	char **stringArray;
	int i;
	int total = 0;
	char *p;
	char *n;
	p = cgiCookie;
	while (*p) {
		if (*p == '=') {
			total++;
		}
		p++;
	}
	stringArray = (char **) malloc(sizeof(char *) * (total + 1));
	if (!stringArray) {
		*result = 0;
		return cgiFormMemory;
	}
	/* initialize all entries to null; the last will stay that way */
	for (i=0; (i <= total); i++) {
		stringArray[i] = 0;
	}
	i = 0;
	p = cgiCookie;
	while (*p) {
		while (*p && isspace(*p)) {
			p++;
		}
		n = p;
		while (*p && (*p != '=')) {
			p++;
		}
		if (p != n) {
			stringArray[i] = (char *) malloc((p - n) + 1);
			if (!stringArray[i]) {
				cgiStringArrayFree(stringArray);
				*result = 0;
				return cgiFormMemory;
			}	
			memcpy(stringArray[i], n, p - n);
			stringArray[i][p - n] = '\0';
			i++;
		}
		while (*p && (*p != ';')) {
			p++;	
		}
		if (!*p) {
			break;
		}
		if (*p == ';') {
			p++;
		}
	}
	*result = stringArray;
	return cgiFormSuccess;
}

cgiFormResultType cgiFormEntries(char ***result) {
	char **stringArray;
	cgiFormEntry *e, *pe;
	int i;
	int total = 0;
	e = cgiFormEntryFirst;
	while (e) {
		/* Don't count a field name more than once if
			multiple values happen to be present for it */
		pe = cgiFormEntryFirst;
		while (pe != e) {
			if (!strcmp(e->attr, pe->attr)) {
				goto skipSecondValue;
			}
			pe = pe->next;					
		}
		total++;
skipSecondValue:
		e = e->next;
	}
	stringArray = (char **) malloc(sizeof(char *) * (total + 1));
	if (!stringArray) {
		*result = 0;
		return cgiFormMemory;
	}
	/* initialize all entries to null; the last will stay that way */
	for (i=0; (i <= total); i++) {
		stringArray[i] = 0;
	}
	/* Now go get the entries */
	e = cgiFormEntryFirst;
	i = 0;
	while (e) {
		int space;
		/* Don't return a field name more than once if
			multiple values happen to be present for it */
		pe = cgiFormEntryFirst;
		while (pe != e) {
			if (!strcmp(e->attr, pe->attr)) {
				goto skipSecondValue2;
			}
			pe = pe->next;					
		}		
		space = (int) strlen(e->attr) + 1;
		stringArray[i] = (char *) malloc(space);
		if (stringArray[i] == 0) {
			/* Memory problems */
			cgiStringArrayFree(stringArray);
			*result = 0;
			return cgiFormMemory;
		}	
		strcpy(stringArray[i], e->attr);
		i++;
skipSecondValue2:
		e = e->next;
	}
	*result = stringArray;
	return cgiFormSuccess;
}

#define TRYPUTC(ch) \
	{ \
		if (putc((ch), cgiOut) == EOF) { \
			return cgiFormIO; \
		} \
	} 

cgiFormResultType cgiHtmlEscapeData(char *data, int len)
{
	while (len--) {
		if (*data == '<') {
			TRYPUTC('&');
			TRYPUTC('l');
			TRYPUTC('t');
			TRYPUTC(';');
		} else if (*data == '&') {
			TRYPUTC('&');
			TRYPUTC('a');
			TRYPUTC('m');
			TRYPUTC('p');
			TRYPUTC(';');
		} else if (*data == '>') {
			TRYPUTC('&');
			TRYPUTC('g');
			TRYPUTC('t');
			TRYPUTC(';');
		} else {
			TRYPUTC(*data);
		}
		data++;
	}
	return cgiFormSuccess;
}

cgiFormResultType cgiHtmlEscape(char *s)
{
	return cgiHtmlEscapeData(s, (int) strlen(s));
}

/* Output data with the " character HTML-escaped, and no
	other characters escaped. This is useful when outputting
	the contents of a tag attribute such as 'href' or 'src'.
	'data' is not null-terminated; 'len' is the number of
	bytes in 'data'. Returns cgiFormIO in the event
	of error, cgiFormSuccess otherwise. */
cgiFormResultType cgiValueEscapeData(char *data, int len)
{
	while (len--) {
		if (*data == '\"') {
			TRYPUTC('&');
			TRYPUTC('#');
			TRYPUTC('3');
			TRYPUTC('4');
			TRYPUTC(';');
		} else {
			TRYPUTC(*data);
		}
		data++;
	}
	return cgiFormSuccess;
}

cgiFormResultType cgiValueEscape(char *s)
{
	return cgiValueEscapeData(s, (int) strlen(s));
}