NAME
system – pass a command to the shell
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdlib.h>
int
system(const char *string);
DESCRIPTION
The system() function hands the argument string to the command interpreter sh(1). The calling process waits for the shell to finish executing the command, ignoring SIGINT and SIGQUIT, and blocking SIGCHLD.
If string is a NULL pointer, system() will return non-zero if the command interpreter sh(1) is available, and zero if it is not.
RETURN VALUES
The system() function returns the exit status of the shell as returned by waitpid(2), or -1 if an error occurred when invoking fork(2) or waitpid(2). If the child process fails to execute the shell, it will terminate with an exit code of 127 and system will return the corresponding exit status.
SEE ALSO
sh(1), execve(2), fork(2), waitpid(2), popen(3), posix_spawn(3)
STANDARDS
The system() function conforms to ISO/IEC 9899:1990 (“ISO C90”) and is expected to be IEEE Std 1003.2 (“POSIX.2”) compatible.
SECURITY CONSIDERATIONS
The system() function is easily misused in a manner that enables a malicious user to run arbitrary commands, because all meta-characters supported by sh(1) would be honored. User supplied parameters should always be carefully sanitized before they appear in string.