Problem - Kevin Tafuro

process is forked, the original process is used to execute another program or the new
process is used to continue primary execution of the program. In other words, the
new process is most often the worker process.
#include
#include
pid_t spc_fork(void) {
pid_t childpid;
if ((childpid = fork( )) = = -1) return -1;
/* Reseed PRNGs in both the parent and the child */
/* See Chapter 11 for examples */
/* If this is the parent process, there's nothing more to do */
if (childpid != 0) return childpid;
/* This is the child process */
spc_sanitize_files( ); /* Close all open files. See Recipe 1.1 */
spc_drop_privileges(1); /* Permanently drop privileges. See Recipe 1.3 */
return 0;
}
See Also
Recipes 1.3, 1.5, 1.7
1.7 Executing External Programs Securely
Problem
Your Unix program needs to execute another program.
Solution
On Unix, one of the exec*( ) family of functions is used to replace the current program
within a process with another program. Typically, when you’re executing
another program, the original program continues to run while the new program is
executed, thus requiring two processes to achieve the desired effect. The exec*( )
functions do not create a new process. Instead, you must first use fork( ) to create a
new process, and then use one of the exec*( ) functions in the new process to run the
new program. See Recipe 1.6 for a discussion of using fork( ) securely.
28 | Chapter 1: Safe Initialization
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