how to open a text file in C code example

Example 1: write in file in c

#include<stdio.h>
int main(){
	FILE *out=fopen("name_of_file.txt","w");
	fputs("Hello File",out);
	fclose(out);
	return 0;
}

Example 2: how to print a file c

c = fgetc(fptr); 
    while (c != EOF) 
    { 
        printf ("%c", c); 
        c = fgetc(fptr); 
    }

Example 3: file in C

//to open a file
FILE=*fp;
fp=fopen("one.txt", "w");
//to close file 
fclose(fp);

Example 4: c read file from command line

You can use as your main function:
int main(int argc, char **argv) 

So, if you entered to run your program:
C:\myprogram myfile.txt

argc will be 2
argv[0] will be myprogram
argv[1] will be myfile.txt

To read the file:
FILE *f = fopen(argv[1], "r");