struct stat sti, sto;
int fin, fout, n;
char target[BUFSIZ], buf[BUFSIZ], *index;
sprintf(target, "%s/%s", dir, file);
if (index(file, '/') != NULL) /* strchr in some systems */
error("won't handle '/'s in %s", file);
if (stat(file, sti) == -1)
error("can't stat %s", file);
if (stat(target, sto) == -1) /* target not present */
sto.st_mtime = 0; /* so make it look old */
if (sti.st_mtime sto.st_mtime) /* target is newer */
fprintf(stderr, "%s: %s not copied\n", progname, file);
else if ((fin = open(file, 0)) == -1)
error("can't open file %s", file);
else if ((fout = creat(target, sti.st_mode)) == -1)
error("can't create %s", target);
while ((n = read(fin, buf, sizeof buf)) 0)
if (write(fout, buf, n) != n)
error("error writing %s", target);
close(fin);
close(fout);
}
#include "error.c"
#include signal.h
system(s) /* run command line s */
char *s;
{
int status, pid, w, tty;
int (*istat), (*qstat);
...
if ((pid = fork) == 0) {
...
execlp("sh", "sh", "-c", s, (char*)0);
exit(127);
}
...
istat = signal(SIGINT, SIG_IGN);
qstat = signal(SIGQUIT, SIG_IGN);
while ((w = wait(status)) != pid w != -1)
;
if (w == -1)
status = -1;
signal(SIGINT, istat);
signal(SIGQUIT, qstat);
return status;
}
/*
* Safer version of system for interactive programs
*/
#include signal.h
#include stdio.h
system(s) /* run command line s */
char *s;
{
int status, pid, w, tty;
int (*istat), (*qstat);
extern char *progname;
fflush(stdout);
tty = open("/dev/tty", 2);
if (tty == -1) {
fprintf (stderr, "%s: can't open /dev/tty\n", progname);
return -1;
}
if ((pid = fork) == 0) {
close(0);
dup(tty);
close(1);
dup(tty);
close(2);
dup(tty);
close(tty);
execlp("sh", "sh", "-c", s, (char*)0);
exit(127);
}
close(tty);
istat = signal(SIGINT, SIG_IGN);
qstat = signal(SIGQUIT, SIG_IGN);
while ((w = wait(status)) != pid w != -1)
;
if (w == -1)
status = -1;
signal(SIGINT, istat);
signal(SIGQUIT, qstat);
return status;
}
/* timeout: set time limit on a process */
#include stdio.h
#include signal.h
int pid; /* child process id */
char *progname;
main(argc, argv)
int argc;
char *argv[];
{
int sec = 10, status, onalarm;
progname = argv[0];
if (argc 1 argv[1][0] == '-') {
sec = atoi(argv[1][1]);
argc--;
argv++;
}
if (argc 2)
error("Usage: %s [-10] command", progname);
if ((pid=fork) == 0) {
execvp(argv[1], argv[1]);
error("couldn't start %s", argv[1]);
}
signal(SIGALRM, onalarm);
alarm(sec);
if (wait(status) == -1 || (status 0177) != 0)
error("%s killed", argv[1]);
exit((status 8) 0377);
}
onalarm /* kill child when alarm arrives */
{
kill(pid, SIGKILL);
}
#include "error.c"