You have to fill in values to a template letter.txt
Letter.txt looks something like this:
Thanks {{name}} for purchasing {{item}} from our outlet {{outlet}}
Please visit our {{outlet}} for any kind of problems. We plan to serve you again
You have to read this file and replace these values:
{{name}} - Harry
{{item}} - Table Fan
{{outlet}} - Ram Laxmi fan outlet
Use file functions in C to accomplish the same
#include <stdio.h>
#include <<tring.h>
#include <stdlib.h>
char *replaceWord(const char *str, const char *oldWord, const char *newWord)
{
char *resultString;
int i, count = 0;
int newWordLength = strlen(newWord);
int oldWordLength = strlen(oldWord);
// Lets count the number of times old word occurs in the string
for (i = 0; str[i] != '\0'; i++)
{
if (strstr(&str[i], oldWord) == &str[i])
{
count++;
// jump over this world
i = i + oldWordLength - 1;
}
}
// making a new string to fit in the replaced words
resultString = (char *)malloc(i + count * (newWordLength - oldWordLength + 1));
i = 0;
while (*str)
{
// compare the substring with result
if (strstr(str, oldWord) == str)
{
strcpy(&resultString[i], newWord);
i += newWordLength;
str += oldWordLength;
}
else
{
resultString[i] = *str;
i += 1;
str += 1;
}
}
resultString[i]='\0';
return resultString;
}
int main()
{
FILE *ptr = NULL;
FILE *ptr2 = NULL;
ptr = fopen("bill.txt", "r");
ptr2 = fopen("genBill.txt", "w");
char str[200];
fgets(str, 200, ptr); // the file content will be stored in 'str'
printf("The bill template was : %s:\n", str);
// call the replaceWord function and generate newStr
char *newStr;
newStr = replaceWord(str, "{{item}}", "Table Fan");
newStr = replaceWord(newStr, "{{outlet}}", "Ram Laxmi fan outlet");
newStr = replaceWord(newStr, "{{name}}", "Harry");
printf("The bill generated is : %s:\n", newStr);
printf("The generated bill has been written to the file genBill.txt\n");
fprintf(ptr2, "%s", newStr);
fclose(ptr);
fclose(ptr2);
return 0;
}