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#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <sys/wait.h>
#include "dietwarning.h"
#include "dietfeatures.h"
#include "binshstr.h"
extern char **environ;
int __libc_system (const char *line);
int __libc_system (const char *line)
{
struct sigaction sa, intr, quit;
sigset_t block,omask;
int save,pid,ret=-1;
if (line == 0) return __libc_system("exit 0") == 0;
sa.sa_handler = SIG_IGN;
sa.sa_flags = 0;
sigemptyset (&sa.sa_mask);
if (sigaction(SIGINT, &sa, &intr)<0) return -1;
if (sigaction(SIGQUIT, &sa, &quit)<0) {
save = errno;
undo:
sigaction (SIGINT, &intr, (struct sigaction*)0);
errno=save;
return -1;
}
sigemptyset(&block);
sigaddset(&block,SIGCHLD);
if (sigprocmask(SIG_BLOCK,&block,&omask)<0) {
save=errno;
sigaction (SIGQUIT, &quit, (struct sigaction*)0);
goto undo;
}
pid=fork();
if (pid>0)
{ /* parent */
int n;
do
n=waitpid(pid, &ret, 0);
while ((n==-1) && (errno==EINTR));
if (n!=pid) ret=-1;
}
else if (!pid)
{ /* child */
const char *nargs[4];
nargs[0] = __sh;
nargs[1] = "-c";
nargs[2] = line;
nargs[3] = 0;
sigaction(SIGINT, &intr, (struct sigaction*)0);
sigaction(SIGQUIT, &quit, (struct sigaction*)0);
sigprocmask(SIG_SETMASK,&omask,0);
execve(__binsh,(char *const *)nargs, environ);
_exit(127);
}
save = errno;
sigaction (SIGINT, &intr, (struct sigaction *)0);
sigaction (SIGQUIT, &quit, (struct sigaction *)0);
sigprocmask(SIG_SETMASK,&omask,0);
errno=save;
return ret;
}
int system (const char *line) __attribute__((weak,alias("__libc_system")));
link_warning("system","warning: system() is a security risk. Use fork and execvp instead!")
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