Data commit

Task/Substitution-cipher/C/substitution-cipher.c

@@ -0,0 +1,64 @@
+#include<stdlib.h>
+#include<stdio.h>
+#include<wchar.h>
+
+#define ENCRYPT 0
+#define DECRYPT 1
+#define ALPHA 33
+#define OMEGA 126
+
+int wideStrLen(wchar_t* str){
+	int i = 0;
+	while(str[i++]!=00);
+	
+	return i;
+}
+
+void processFile(char* fileName,char plainKey, char cipherKey,int flag){
+	
+	FILE* inpFile = fopen(fileName,"r");
+	FILE* outFile;
+	
+	int i,len, diff = (flag==ENCRYPT)?(int)cipherKey - (int)plainKey:(int)plainKey - (int)cipherKey;
+	wchar_t str[1000], *outStr;
+	char* outFileName = (char*)malloc((strlen(fileName)+5)*sizeof(char));
+
+	sprintf(outFileName,"%s_%s",fileName,(flag==ENCRYPT)?"ENC":"DEC");
+	
+	outFile = fopen(outFileName,"w");
+	
+	while(fgetws(str,1000,inpFile)!=NULL){
+		len = wideStrLen(str);
+		
+		outStr = (wchar_t*)malloc((len + 1)*sizeof(wchar_t));
+		
+		for(i=0;i<len;i++){
+			if((int)str[i]>=ALPHA && (int)str[i]<=OMEGA && flag == ENCRYPT)
+				outStr[i] = (wchar_t)((int)str[i]+diff);
+			 else if((int)str[i]-diff>=ALPHA && (int)str[i]-diff<=OMEGA && flag == DECRYPT)
+				outStr[i] = (wchar_t)((int)str[i]-diff);
+			else
+				outStr[i] = str[i];
+		}
+		outStr[i]=str[i];
+		
+		fputws(outStr,outFile);
+		
+		free(outStr);
+	}
+	
+	fclose(inpFile);
+	fclose(outFile);
+}
+
+int main(int argC,char* argV[]){
+	if(argC!=5)
+		printf("Usage : %s <file name, plain key, cipher key, action (E)ncrypt or (D)ecrypt>",argV[0]);
+	else{
+		processFile(argV[1],argV[2][0],argV[3][0],(argV[4][0]=='E'||argV[4][0]=='e')?ENCRYPT:DECRYPT);
+		
+		printf("File %s_%s has been written to the same location as input file.",argV[1],(argV[4][0]=='E'||argV[4][0]=='e')?"ENC":"DEC");
+	}
+	
+	return 0;
+}