Use the %lf format specifier to read a double: double a; scanf(“%lf”,&a); Wikipedia has a decent reference for available format specifiers. You’ll need to use the %lf format specifier to print out the results as well: printf(“%lf %lf”,a,b);
You have no storage allocated for word – it’s just a dangling pointer. Change: char * word; to: char word[256]; Note that 256 is an arbitrary choice here – the size of this buffer needs to be greater than the largest possible string that you might encounter. Note also that fgets is a better (safer) … Read more
You have 3 choices: atoi This is probably the fastest if you’re using it in performance-critical code, but it does no error reporting. If the string does not begin with an integer, it will return 0. If the string contains junk after the integer, it will convert the initial part and ignore the rest. If … Read more
Because there’s no portable way for a variable argument functions like scanf and printf to know the types of the variable arguments, not even how many arguments are passed. See C FAQ: How can I discover how many arguments a function was actually called with? This is the reason there must be at least one … Read more
So many problems in so few lines. I probably forget some: argv[0] is the program name, not the first argument; if you want to read in a variable, you have to allocate its memory one never loops on feof, one loops on an IO function until it fails, feof then serves to determinate the reason … Read more
There is also the parse module. parse() is designed to be the opposite of format() (the newer string formatting function in Python 2.6 and higher). >>> from parse import parse >>> parse(‘{} fish’, ‘1’) >>> parse(‘{} fish’, ‘1 fish’) <Result (‘1’,) {}> >>> parse(‘{} fish’, ‘2 fish’) <Result (‘2’,) {}> >>> parse(‘{} fish’, ‘red fish’) … Read more
Most of the answers so far seem to focus on the string buffer overflow issue. In reality, the format specifiers that can be used with scanf functions support explicit field width setting, which limit the maximum size of the input and prevent buffer overflow. This renders the popular accusations of string-buffer overflow dangers present in … Read more
Enter while securing an area dynamically E.G. #include <stdio.h> #include <stdlib.h> char *inputString(FILE* fp, size_t size){ //The size is extended by the input with the value of the provisional char *str; int ch; size_t len = 0; str = realloc(NULL, sizeof(*str)*size);//size is start size if(!str)return str; while(EOF!=(ch=fgetc(fp)) && ch != ‘\n’){ str[len++]=ch; if(len==size){ str = … Read more
In their book The Practice of Programming (which is well worth reading), Kernighan and Pike discuss this problem, and they solve it by using snprintf() to create the string with the correct buffer size for passing to the scanf() family of functions. In effect: int scanner(const char *data, char *buffer, size_t buflen) { char format[32]; … Read more
Use: fgets (name, 100, stdin); 100 is the max length of the buffer. You should adjust it as per your need. Use: scanf (“%[^\n]%*c”, name); The [] is the scanset character. [^\n] tells that while the input is not a newline (‘\n’) take input. Then with the %*c it reads the newline character from the … Read more