Contents
Why is printf unsafe?
In general, sloppy usage of the functions printf(), sprintf(), fprintf(), and so on, not only can lead to incorrect work of the program, but cause potential vulnerabilities, that someone can take advantage of. Written by Andrey Karpov. This error was found with PVS-Studio static analysis tool.
Is it bad to use printf in C++?
Nope, but it is unsafe, look at this code: printf(“Hello %s\n”);
Can printf fail?
printf function in c doesn’t always print the output on screen. For example if you forget to put \n at the end of string you are printfing you sometimes don’t get the o/p.
What are bugs in C programming?
A software bug is an error, flaw or fault in a computer program or system that causes it to produce an incorrect or unexpected result, or to behave in unintended ways. Bugs can trigger errors that may have ripple effects. Bugs may have subtle effects or cause the program to crash or freeze the computer.
What can I use instead of printf?
puts() can be preferred for printing a string because it is generally less expensive (implementation of puts() is generally simpler than printf()), and if the string has formatting characters like ‘%s’, then printf() would give unexpected results.
How do I flush printf buffer?
If you need to see the output, you need to make sure the buffer is flushed. You can do this for an _IOLBF stream by making sure to end each printf format string with a ‘\n’ (new line). Since the stdout stream is line buffered this will cause the buffer to be flushed.
Is it OK to use printf in a program?
Everybody has heard of software vulnerabilities and that functions like printf are outlaw. However, it’s one thing to know that you’d better not use these functions, and quite the other to understand why.
How does the printf ( ) function in Java work?
The printf () function refers to the family of variable-argument functions. These functions work in the following way. Some amount of data is written into the stack. The printf () function doesn’t know the amount of data that is pushed and what type it has. It follows only the format string.
When to use printf ( ) to debug a program?
In general, if you add printf()calls, you should print as much information as possible. For example, the meaning of the output “here”quickly gets lost. The ouput “DEBUG: i=27; count=35″conveys much more. But, inserting printf()code in your program has a major disadvantage.
Is there an attack based on the printf ( ) specifier?
It allows writing a number of characters, already printed by the printf () function, by a certain address. To be honest, an attack based on the %n specifier is just of a historical character. Starting with Visual Studio 2005, the capability of using %n is off by default.