User.

#include <stdio.h>
#include <string.h>
#include <cs50.h>
#include <ctype.h>

int main (void) {
char jop=get_char("Find user <f> Add user <a>\n");
jop=tolower(jop);
FILE *user;

/********************************Find user***********************/
if(jop == 'f'){
char *u_name=get_string("Username: ");
char *u_inf=malloc(strlen(u_name)+5);
strcpy(u_inf, u_name);
sprintf(u_inf,"%s.txt",u_name);
//read file
user=fopen(u_inf,"r");
//Check if User is null
if(user == NULL){
    fprintf(stderr,"Couldn't find user\n");
    fclose(user);
    return 2;
}
//Get data from file
fread(u_inf,strlen(u_name)+19,1,user);
printf("Password: %s\n",u_inf);
fclose(user);
return 0;
/********************************Add user***********************/
}
if(jop == 'a'){
char *u_name=get_string("Username: ");
char *u_inf=malloc(strlen(u_name)+5);
strcpy(u_inf, u_name);
sprintf(u_inf,"%s.txt",u_name);
//Write and read file
user=fopen(u_inf,"w+");
//Check if User was null
if(user == NULL){
    fprintf(stderr,"Couldn't add user\n");
    fclose(user);
    return 3;
}
//Get password from user
string u_password=get_string("Password: ");
//Check if password was null
if(u_password == NULL){
    fprintf(stderr,"Couldn't get password\n");
    fclose(user);
    return 4;
    }
//Check if password wasn't more than 13
    if(strlen(u_password)>13){
    fprintf(stderr,"Error password max lenth is 13\n");
    fclose(user);
    return 5;
    }
     sprintf(u_inf,"%s",u_password);
//write file
    fwrite(u_inf,strlen(u_inf)+1,1,user);
    fseek(user,strlen(u_inf)+1,SEEK_SET);
    fprintf(stderr,"file created successful\n");
    fclose(user);
    return 0;
}
if(jop!='a'|| jop!='f'){
    fprintf(stderr,"Error\n");
    return 1;
}
}