[rfc][icedtea-web] read properties values from C part - library edition :)

[Jiri Vanek]

Replacing harcoded jre path - part 3, intermezzo.

This code should allow to parse properties from plugin side. As I can not find jvm by launching jvm 
O:)   - as Saad did.

Please be kind to me, I'm removing dust from my C coding just slowly ;)

Later the empty getPluginExecutbale and getPluginRtJar  from "[rfc][icedtea-web] replacing of 
hardcoded jre path by function" should call the findCustomJre and provide its value(if found) 
instead of default one (but still provide default as fallback)

I will probably also substitute Saad's code (which is launching jvm to get property. It is 
significant performance drop) with this new getDeployProperty method later.

J.

ps: this is part of make-jredir-configurable after install effort
-------------- next part --------------
#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <wordexp.h>
#include <string.h>

//public api
char*  getUserPropertiesFile();
int    findSystemConfigFile(char* dest);
int    findCustomJre(char* dest);
int    getDeployProperty(char* property, char* dest);
//end of public api

static void popChar(char *c, int x){
	int i;
	for ( i = x; i <=  strlen(c); i++){//moving also \0
		if (i > x){
			c[i-1] = c[i];
		}
	}
}

static void removeSpaces(char *c){
	int i;
	for ( i = 0; i <  strlen(c); i++){
		if ( c[i] == ' ') {
			popChar(c,i);
			i--;
		}
	}
}

static void removeStartSpaces(char *c){
	int i;
	for ( i = 0; i <  strlen(c); i++){
		if ( c[i] == ' ' || c[i] == '\n' ) {
			popChar(c,i);
			i--;
		} else return;
	}
}

static void removeTailSpaces(char *c){
	int i;
	for ( i =  strlen(c)-1 ; i >- 0; i--){
		if ( c[i] == ' ' || c[i] == '\n' ) {
			popChar(c,i);
		} else return;
	}
}

static void trim(char *c){
	removeTailSpaces(c);
	removeStartSpaces(c);
}

static void clean(char *c){
	int i;
	for ( i = 0; i <  strlen(c); i++){
		c[i] = '\0';
	}
}


static int equalsPos(char *c){
	int i;
	for ( i = 0; i <  strlen(c); i++){
		if ( c[i] == '=') {
			return i;
		}
	}
return -1;
}

static char*  getPropertyValue(char* c, char* dest){
	int i = equalsPos(c);
	if (i == -1) c;
	int l = strlen(c);
	strncpy(dest, c+i+1, l-i);
	trim(dest);
	return dest;
}


static int startsWith(char *c1, char* c2){
	int i;
	int l1 = strlen(c1);
	int l2 = strlen(c2);
	int min = l1;
	if (l1 > l2) min = l2;
	for ( i = 0; i <  min; i++){
		if ( c1[i] != c2[i]) {
			return 1; //fasle
		}
	}
	return 0;//true
}


char*  getUserPropertiesFile(){
 struct passwd *pw = getpwuid(getuid());
	wordexp_t exp_result;
	wordexp("~/.icedtea/deployment.properties", &exp_result, 0);
	return exp_result.we_wordv[0];
}


static char*  getMainPropertiesFile(){
	return "/etc/.java/deployment/deployment.properties";
}

static char * getDefaultJavaPropertiesFile(){
	return  ICEDTEA_WEB_JRE "/lib/deployment.properties";
}


//this is reimplemntation as icedtea-web settings do this (Also name of function is the same):
//try  the main file in /etc/.java/deployment
//if found, then return this file
//try to find setUp jre
//  if found, then try if this file exists and end
//if no jre custom jvm is set, then tryes default jre
//  if its  deploy file exists, then return
//not dound otherwise
int findSystemConfigFile(char* dest){
	if(access(getMainPropertiesFile(), F_OK ) != -1 ) {
		strcpy(dest, getMainPropertiesFile());
		return 0;//file found
	} else {
		char jDest[512];
		int customJre = findCustomJre(jDest);
		if (customJre == 0){
			strncat(jDest,"/lib/deployment.properties",50);
			if(access(jDest, F_OK ) != -1 ) {
				strcpy(dest, jDest);
				return 0; //file found
			} 
		} else {
			if(access(getDefaultJavaPropertiesFile(), F_OK ) != -1 ) {
			strcpy(dest, getDefaultJavaPropertiesFile());
			return 0; //file found
			} 
		}	
	}
return 1; //nothing of above found
}

//returns true if found, false otherwise
static int  findProperty(char* fileName, char* property, char* dest){
	char nwprpty[strlen(property) + 2];
	strcpy(nwprpty, property);
	strcat(nwprpty, "=");
	FILE *file = fopen ( fileName, "r" );
	if ( file != NULL ){
		char line [ 512 ]; /* or other suitable maximum line size */
		while ( fgets ( line, sizeof line, file ) != NULL ){ /* read a line */
			char copy[512];
			strcpy(copy, line);
			//java tolerates sapces arround = char, remove them for matching
			removeSpaces(copy);
			//printf(line);
			//printf(copy);
			if (startsWith(copy,nwprpty) == 0) {
				fclose (file);
				//provide non-sapced value, triming is  done in getPropertyValue
				getPropertyValue(line,dest);
				return 0;//found!
				}
			}

		}else{
			perror (fileName); /* why didn't the file open? */
		}
	return 1;//not found:(
	}


//this is reimplmentation of itw-settings operations
//first check in user's settings, if found, return
//then check in global file (see the magic of findSystemConfigFile)
int  getDeployProperty(char* property, char* dest){
	//is it in user's file?
	int a = findProperty(getUserPropertiesFile(), property, dest);
	if (a == 0) return 0;
	//is it in global file?
	char file[512];
	int b = findSystemConfigFile(file);
	if (b == 0) {
		return findProperty(file, property, dest);
	}
	return 1;
}

//This is different from common get property, as it is avoiding to search in *java*
//properties files
int  findCustomJre(char* dest){
	char* key = "deployment.jre.dir";
	int a = findProperty(getUserPropertiesFile(),key, dest);
	if (a == 0) return 0;
	int b = findProperty(getMainPropertiesFile(),key, dest);
	return b;
	
}



int main(void){
	printf(getUserPropertiesFile());
	printf("\n");
	printf(getMainPropertiesFile());
	printf("\n");
	printf(getDefaultJavaPropertiesFile());
	printf("\n");
	char dest1[512];
	clean(dest1);
	int i1 = findSystemConfigFile(dest1);
	printf(dest1);
	printf("\n");
	char dest2[512];
	clean(dest2);
	int i2 = findCustomJre(dest2);
	printf(dest2);
	printf("\n");
	char dest3[512];
	clean(dest3);
	int i3 = getDeployProperty("deployment.security.level", dest3);
	printf(dest3);
	printf("\n");
  return 0;
}