How to write text from file to a string in C

Question

I want to write code were the user is asked to write the name of a file. Then I want to analyze the file's content for a symbol, let's say 'e'.

My problem is that I don't know how to start analyzing the file the correct way so that the content can be checked.

int main() {
    char c[1000], file_name[1000];
    int i;
    int s = 0;
    FILE *fp;

    printf("Enter the name of file you wish to see\n");
    gets(file_name);

    if ((fp = fopen(file_name, "r")) == NULL){
        printf("Error! opening file");
        exit(1);

    }

    if (fp) {
        while (fscanf(fp, "%s", c) != EOF) {
            printf("%s", c);
        }

        fclose(fp);

        for (i = 0; c[i] != '\0'; ++i) {
            puts(c);
            if (c[i] == 'e') {
                ++s;
            }
        }

        printf("\nWhite spaces: %d", s);
        _getche();
        return 0;
    }
}

Well to save the contents of the file to a string so i can run c[i] — Veselin Lalov
– Veselin Lalov, Commented Dec 11, 2014 at 18:31
you will need a char* where you will store all the content. Then, inside your while loop, do strcat(myFullString, c); this will append the new content to the "myFullString" array and you will then be able to use is in your for loop Look at this example: programmingsimplified.com/c-program-concatenate-strings — RAEC
– RAEC, Commented Dec 11, 2014 at 18:34
I must add a char pointer if i understand correctly ? I am verry sorry i am verry new to C and programing at all, but i am very passionate about it. — Veselin Lalov
– Veselin Lalov, Commented Dec 11, 2014 at 18:37
Are you looking for fread() ? cplusplus.com/reference/cstdio/fread Try fread(c,sizeof(char),1000,fp); Remember that in this case, c is an array of char, not a string. If you want c to remain a string : fread(c,sizeof(char),999,fp);c[999]='\0'; — francis
– francis, Commented Dec 11, 2014 at 18:44

Sam · Accepted Answer · 2014-12-11 20:29:35Z

2

char line[512]; /*To fetch a line from file maximum of 512 char*/
rewind(fp);
memset(line,0,sizeof(line)); /*Initialize to NULL*/
while ( fgets(line, 512, fp ) && fp !=EOF)
{

/*Suppose u want to analyze string "WELL_DONE" in this fetched line.*/

  if(strstr(line,"WELL_DONE")!=NULL)
  {
    printf("\nFOUND KEYWOD!!\n");
  }
  memset(line,0,sizeof(line)); /*Initialize to null to fetch again*/
}

answered Dec 11, 2014 at 20:29

Sam

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Comments

buydadip · Accepted Answer · 2014-12-11 22:15:27Z

1

If its just a symbol you're looking for, or a char, you can simply use getc() :

int c;
....
if (fp) {
    while ((c = getc(fp)) != EOF) {
        if (c == 'e') {
            // Do what you need
        }
    }

Or, alternatively, if it's a word you're looking for, fscanf() will do the job:

int c;
char symb[100];
char symbToFind[] = "watever";  // This is the word you're looking for
....
while ((c = fscanf(fp, %s, symb)) != EOF) {
    if (strcmp(symb, symbToFind) == 0) {  // strcmp will compare every word in the file
        // do whatever                    // to symbToFind
    }
}

These alternatives will allow you to search every char or string in the file, without having to save them as an array.

edited Dec 11, 2014 at 22:15

answered Dec 11, 2014 at 22:06

buydadip

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