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SYSTEM(3) BSD Library Functions Manual SYSTEM(3) 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 execut- ing the command, ignoring SIGINT and SIGQUIT, and blocking SIGCHLD. If string is a NULL pointer, system() will return non-zero, if the command interpreter is available, or zero if none is available. Other- wise, system() returns the termination status of the shell in the format specified by waitpid(2). RETURN VALUES
If a child process cannot be created, or the termination status of the shell cannot be obtained, system() returns -1 and sets errno to indi- cate the error. If execution of the shell fails, system() returns the termination status for a program that terminates with a call of exit(127). SEE ALSO
sh(1), execve(2), waitpid(2), popen(3), shquote(3) STANDARDS
The system() function conforms to ANSI X3.159-1989 (``ANSI C89'') and IEEE Std 1003.2-1992 (``POSIX.2''). CAVEATS
Never supply the system() function with a command containing any part of an unsanitized user-supplied string. Shell meta-characters present will be honored by the sh(1) command interpreter. BSD
August 2, 2007 BSD