* Wed Jun 22 21:41:56 1994, faith@cs.unc.edu:
* Added fix from Mike Grupenhoff (kashmir@umiacs.umd.edu)
* Mon Jul 1 17:01:39 MET DST 1996, janl@math.uio.no:
- * - Added fix from David.Chapell@mail.trincoll.edu enabeling daemons
+ * - Added fix from David.Chapell@mail.trincoll.edu enabling daemons
* to use write.
* - ANSIed it since I was working on it anyway.
- * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
+ * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
* - added Native Language Support
*
*/
-#include <stdio.h>
-#include <unistd.h>
-#include <utmp.h>
#include <errno.h>
-#include <time.h>
+#include <getopt.h>
+#include <paths.h>
#include <pwd.h>
-#include <string.h>
-#include <stdlib.h>
#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
-#include <paths.h>
-#include <asm/param.h>
-#include <getopt.h>
+#include <time.h>
+#include <unistd.h>
+#include <utmpx.h>
#include "c.h"
#include "carefulputc.h"
#include "closestream.h"
#include "nls.h"
-
-static void __attribute__ ((__noreturn__)) usage(FILE * out);
-void search_utmp(char *, char *, char *, uid_t);
-void do_write(char *, char *, uid_t);
-void wr_fputs(char *);
-static void __attribute__ ((__noreturn__)) done(int);
-int term_chk(char *, int *, time_t *, int);
-int utmp_chk(char *, char *);
-
-static gid_t myegid;
-
-static void __attribute__ ((__noreturn__)) usage(FILE * out)
+#include "strutils.h"
+#include "ttyutils.h"
+#include "xalloc.h"
+
+static sig_atomic_t signal_received = 0;
+
+struct write_control {
+ uid_t src_uid;
+ const char *src_login;
+ const char *src_tty_path;
+ const char *src_tty_name;
+ const char *dst_login;
+ char *dst_tty_path;
+ const char *dst_tty_name;
+};
+
+static void __attribute__((__noreturn__)) usage(void)
{
- fputs(_("\nUsage:\n"), out);
+ FILE *out = stdout;
+ fputs(USAGE_HEADER, out);
fprintf(out,
_(" %s [options] <user> [<ttyname>]\n"),
program_invocation_short_name);
- fputs(_("\nOptions:\n"), out);
- fputs(_(" -V, --version output version information and exit\n"
- " -h, --help display this help and exit\n\n"), out);
+ fputs(USAGE_SEPARATOR, out);
+ fputs(_("Send a message to another user.\n"), out);
- exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+ fputs(USAGE_OPTIONS, out);
+ printf(USAGE_HELP_OPTIONS(16));
+ printf(USAGE_MAN_TAIL("write(1)"));
+ exit(EXIT_SUCCESS);
}
-int main(int argc, char **argv)
+/*
+ * check_tty - check that a terminal exists, and get the message bit
+ * and the access time
+ */
+static int check_tty(const char *tty, int *tty_writeable, time_t *tty_atime, int showerror)
{
- time_t atime;
- uid_t myuid;
- int msgsok, myttyfd, c;
- char tty[MAXPATHLEN], *mytty;
-
- static const struct option longopts[] = {
- {"version", no_argument, NULL, 'V'},
- {"help", no_argument, NULL, 'h'},
- {NULL, 0, NULL, 0}
- };
-
- setlocale(LC_ALL, "");
- bindtextdomain(PACKAGE, LOCALEDIR);
- textdomain(PACKAGE);
- atexit(close_stdout);
+ struct stat s;
- while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
- switch (c) {
- case 'V':
- printf(_("%s from %s\n"),
- program_invocation_short_name,
- PACKAGE_STRING);
- return EXIT_SUCCESS;
- case 'h':
- usage(stdout);
- default:
- usage(stderr);
+ if (stat(tty, &s) < 0) {
+ if (showerror)
+ warn("%s", tty);
+ return 1;
+ }
+ if (getuid() == 0) /* root can always write */
+ *tty_writeable = 1;
+ else {
+ if (getegid() != s.st_gid) {
+ warnx(_("effective gid does not match group of %s"), tty);
+ return 1;
}
-
- myegid = getegid();
-
- /* check that sender has write enabled */
- if (isatty(fileno(stdin)))
- myttyfd = fileno(stdin);
- else if (isatty(fileno(stdout)))
- myttyfd = fileno(stdout);
- else if (isatty(fileno(stderr)))
- myttyfd = fileno(stderr);
- else
- myttyfd = -1;
-
- if (myttyfd != -1) {
- if (!(mytty = ttyname(myttyfd)))
- errx(EXIT_FAILURE,
- _("can't find your tty's name"));
-
- /*
- * We may have /dev/ttyN but also /dev/pts/xx. Below,
- * term_chk() will put "/dev/" in front, so remove that
- * part.
- */
- if (!strncmp(mytty, "/dev/", 5))
- mytty += 5;
- if (term_chk(mytty, &msgsok, &atime, 1))
- exit(EXIT_FAILURE);
- if (!msgsok)
- errx(EXIT_FAILURE,
- _("you have write permission turned off"));
-
- } else
- mytty = "<no tty>";
-
- myuid = getuid();
-
- /* check args */
- switch (argc) {
- case 2:
- search_utmp(argv[1], tty, mytty, myuid);
- do_write(tty, mytty, myuid);
- break;
- case 3:
- if (!strncmp(argv[2], "/dev/", 5))
- argv[2] += 5;
- if (utmp_chk(argv[1], argv[2]))
- errx(EXIT_FAILURE,
- _("%s is not logged in on %s"),
- argv[1], argv[2]);
- if (term_chk(argv[2], &msgsok, &atime, 1))
- exit(EXIT_FAILURE);
- if (myuid && !msgsok)
- errx(EXIT_FAILURE,
- _("%s has messages disabled on %s"),
- argv[1], argv[2]);
- do_write(argv[2], mytty, myuid);
- break;
- default:
- usage(stderr);
+ *tty_writeable = s.st_mode & S_IWGRP;
}
-
- done(0);
- /* NOTREACHED */
- return EXIT_FAILURE;
+ if (tty_atime)
+ *tty_atime = s.st_atime;
+ return 0;
}
-
/*
- * utmp_chk - checks that the given user is actually logged in on
+ * check_utmp - checks that the given user is actually logged in on
* the given tty
*/
-int utmp_chk(char *user, char *tty)
+static int check_utmp(const struct write_control *ctl)
{
- struct utmp u;
- struct utmp *uptr;
+ struct utmpx *u;
int res = 1;
- utmpname(_PATH_UTMP);
- setutent();
+ utmpxname(_PATH_UTMP);
+ setutxent();
- while ((uptr = getutent())) {
- memcpy(&u, uptr, sizeof(u));
- if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0 &&
- strncmp(tty, u.ut_line, sizeof(u.ut_line)) == 0) {
+ while ((u = getutxent())) {
+ if (strncmp(ctl->dst_login, u->ut_user, sizeof(u->ut_user)) == 0 &&
+ strncmp(ctl->dst_tty_name, u->ut_line, sizeof(u->ut_line)) == 0) {
res = 0;
break;
}
}
- endutent();
+ endutxent();
return res;
}
* Special case for writing to yourself - ignore the terminal you're
* writing from, unless that's the only terminal with messages enabled.
*/
-void search_utmp(char *user, char *tty, char *mytty, uid_t myuid)
+static void search_utmp(struct write_control *ctl)
{
- struct utmp u;
- struct utmp *uptr;
- time_t bestatime, atime;
- int nloggedttys, nttys, msgsok, user_is_me;
- char atty[sizeof(u.ut_line) + 1];
-
- utmpname(_PATH_UTMP);
- setutent();
-
- nloggedttys = nttys = 0;
- bestatime = 0;
- user_is_me = 0;
- while ((uptr = getutent())) {
- memcpy(&u, uptr, sizeof(u));
- if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0) {
- ++nloggedttys;
- strncpy(atty, u.ut_line, sizeof(u.ut_line));
- atty[sizeof(u.ut_line)] = '\0';
- if (term_chk(atty, &msgsok, &atime, 0))
- /* bad term? skip */
- continue;
- if (myuid && !msgsok)
- /* skip ttys with msgs off */
- continue;
- if (strcmp(atty, mytty) == 0) {
- user_is_me = 1;
- /* don't write to yourself */
- continue;
- }
- if (u.ut_type != USER_PROCESS)
- /* it's not a valid entry */
- continue;
- ++nttys;
- if (atime > bestatime) {
- bestatime = atime;
- strcpy(tty, atty);
- }
+ struct utmpx *u;
+ time_t best_atime = 0, tty_atime;
+ int num_ttys = 0, valid_ttys = 0, tty_writeable = 0, user_is_me = 0;
+ char path[sizeof(u->ut_line) + 6];
+
+ utmpxname(_PATH_UTMP);
+ setutxent();
+
+ while ((u = getutxent())) {
+ if (strncmp(ctl->dst_login, u->ut_user, sizeof(u->ut_user)) != 0)
+ continue;
+ num_ttys++;
+ sprintf(path, "/dev/%s", u->ut_line);
+ if (check_tty(path, &tty_writeable, &tty_atime, 0))
+ /* bad term? skip */
+ continue;
+ if (ctl->src_uid && !tty_writeable)
+ /* skip ttys with msgs off */
+ continue;
+ if (strcmp(u->ut_line, ctl->src_tty_name) == 0) {
+ user_is_me = 1;
+ /* don't write to yourself */
+ continue;
+ }
+ if (u->ut_type != USER_PROCESS)
+ /* it's not a valid entry */
+ continue;
+ valid_ttys++;
+ if (best_atime < tty_atime) {
+ best_atime = tty_atime;
+ free(ctl->dst_tty_path);
+ ctl->dst_tty_path = xstrdup(path);
+ ctl->dst_tty_name = ctl->dst_tty_path + 5;
}
}
- endutent();
- if (nloggedttys == 0)
- errx(EXIT_FAILURE, _("%s is not logged in"), user);
- if (nttys == 0) {
+ endutxent();
+ if (num_ttys == 0)
+ errx(EXIT_FAILURE, _("%s is not logged in"), ctl->dst_login);
+ if (valid_ttys == 0) {
if (user_is_me) {
/* ok, so write to yourself! */
- strcpy(tty, mytty);
+ if (!ctl->src_tty_path)
+ errx(EXIT_FAILURE, _("can't find your tty's name"));
+ ctl->dst_tty_path = xstrdup(ctl->src_tty_path);
+ ctl->dst_tty_name = ctl->dst_tty_path + 5;
return;
}
- errx(EXIT_FAILURE, _("%s has messages disabled"), user);
- } else if (nttys > 1) {
- warnx(_("%s is logged in more than once; writing to %s"),
- user, tty);
+ errx(EXIT_FAILURE, _("%s has messages disabled"), ctl->dst_login);
}
+ if (1 < valid_ttys)
+ warnx(_("%s is logged in more than once; writing to %s"),
+ ctl->dst_login, ctl->dst_tty_name);
}
/*
- * term_chk - check that a terminal exists, and get the message bit
- * and the access time
+ * signal_handler - cause write loop to exit
*/
-int term_chk(char *tty, int *msgsokP, time_t * atimeP, int showerror)
+static void signal_handler(int signo)
{
- struct stat s;
- char path[MAXPATHLEN];
+ signal_received = signo;
+}
- if (strlen(tty) + 6 > sizeof(path))
- return 1;
- sprintf(path, "/dev/%s", tty);
- if (stat(path, &s) < 0) {
- if (showerror)
- warn("%s", path);
- return 1;
- }
+/*
+ * write_line - like fputs(), but makes control characters visible and
+ * turns \n into \r\n.
+ */
+static void write_line(char *s)
+{
+ while (*s) {
+ const int c = *s++;
- /* group write bit and group ownership */
- *msgsokP = (s.st_mode & (S_IWRITE >> 3)) && myegid == s.st_gid;
- *atimeP = s.st_atime;
- return 0;
+ if ((c == '\n' && fputc_careful('\r', stdout, '^') == EOF)
+ || fputc_careful(c, stdout, '^') == EOF)
+ err(EXIT_FAILURE, _("carefulputc failed"));
+ }
}
/*
* do_write - actually make the connection
*/
-void do_write(char *tty, char *mytty, uid_t myuid)
+static void do_write(const struct write_control *ctl)
{
- char *login, *pwuid, *nows;
+ char *login, *pwuid;
struct passwd *pwd;
time_t now;
- char path[MAXPATHLEN], host[MAXHOSTNAMELEN], line[512];
+ struct tm *tm;
+ char *host, line[512];
+ struct sigaction sigact;
/* Determine our login name(s) before the we reopen() stdout */
- if ((pwd = getpwuid(myuid)) != NULL)
+ if ((pwd = getpwuid(ctl->src_uid)) != NULL)
pwuid = pwd->pw_name;
else
pwuid = "???";
if ((login = getlogin()) == NULL)
login = pwuid;
- if (strlen(tty) + 6 > sizeof(path))
- errx(EXIT_FAILURE, _("tty path %s too long"), tty);
- snprintf(path, sizeof(path), "/dev/%s", tty);
- if ((freopen(path, "w", stdout)) == NULL)
- err(EXIT_FAILURE, "%s", path);
+ if ((freopen(ctl->dst_tty_path, "w", stdout)) == NULL)
+ err(EXIT_FAILURE, "%s", ctl->dst_tty_path);
- signal(SIGINT, done);
- signal(SIGHUP, done);
+ sigact.sa_handler = signal_handler;
+ sigemptyset(&sigact.sa_mask);
+ sigact.sa_flags = 0;
+ sigaction(SIGINT, &sigact, NULL);
+ sigaction(SIGHUP, &sigact, NULL);
+ host = xgethostname();
+ if (!host)
+ host = xstrdup("???");
+
+ now = time((time_t *)NULL);
+ tm = localtime(&now);
/* print greeting */
- if (gethostname(host, sizeof(host)) < 0)
- strcpy(host, "???");
- now = time((time_t *) NULL);
- nows = ctime(&now);
- nows[16] = '\0';
- printf("\r\n\007\007\007");
+ printf("\r\n\a\a\a");
if (strcmp(login, pwuid))
- printf(_("Message from %s@%s (as %s) on %s at %s ..."),
- login, host, pwuid, mytty, nows + 11);
+ printf(_("Message from %s@%s (as %s) on %s at %02d:%02d ..."),
+ login, host, pwuid, ctl->src_tty_name,
+ tm->tm_hour, tm->tm_min);
else
- printf(_("Message from %s@%s on %s at %s ..."),
- login, host, mytty, nows + 11);
+ printf(_("Message from %s@%s on %s at %02d:%02d ..."),
+ login, host, ctl->src_tty_name,
+ tm->tm_hour, tm->tm_min);
+ free(host);
printf("\r\n");
- while (fgets(line, sizeof(line), stdin) != NULL)
- wr_fputs(line);
-}
-
-/*
- * done - cleanup and exit
- */
-static void __attribute__ ((__noreturn__))
- done(int dummy __attribute__ ((__unused__)))
-{
+ while (fgets(line, sizeof(line), stdin) != NULL) {
+ if (signal_received)
+ break;
+ write_line(line);
+ }
printf("EOF\r\n");
- _exit(EXIT_SUCCESS);
}
-/*
- * wr_fputs - like fputs(), but makes control characters visible and
- * turns \n into \r\n.
- */
-void wr_fputs(char *s)
+int main(int argc, char **argv)
{
- char c;
+ int tty_writeable = 0, c;
+ struct write_control ctl = { 0 };
-#define PUTC(c) if (carefulputc(c, stdout) == EOF) \
- err(EXIT_FAILURE, _("carefulputc failed"));
- while (*s) {
- c = *s++;
- if (c == '\n')
- PUTC('\r');
- PUTC(c);
+ static const struct option longopts[] = {
+ {"version", no_argument, NULL, 'V'},
+ {"help", no_argument, NULL, 'h'},
+ {NULL, 0, NULL, 0}
+ };
+
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+ atexit(close_stdout);
+
+ while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
+ switch (c) {
+ case 'V':
+ printf(UTIL_LINUX_VERSION);
+ return EXIT_SUCCESS;
+ case 'h':
+ usage();
+ default:
+ errtryhelp(EXIT_FAILURE);
+ }
+
+ if (get_terminal_name(&ctl.src_tty_path, &ctl.src_tty_name, NULL) == 0) {
+ /* check that sender has write enabled */
+ if (check_tty(ctl.src_tty_path, &tty_writeable, NULL, 1))
+ exit(EXIT_FAILURE);
+ if (!tty_writeable)
+ errx(EXIT_FAILURE,
+ _("you have write permission turned off"));
+ tty_writeable = 0;
+ } else
+ ctl.src_tty_name = "<no tty>";
+
+ ctl.src_uid = getuid();
+
+ /* check args */
+ switch (argc) {
+ case 2:
+ ctl.dst_login = argv[1];
+ search_utmp(&ctl);
+ do_write(&ctl);
+ break;
+ case 3:
+ ctl.dst_login = argv[1];
+ if (!strncmp(argv[2], "/dev/", 5))
+ ctl.dst_tty_path = xstrdup(argv[2]);
+ else
+ xasprintf(&ctl.dst_tty_path, "/dev/%s", argv[2]);
+ ctl.dst_tty_name = ctl.dst_tty_path + 5;
+ if (check_utmp(&ctl))
+ errx(EXIT_FAILURE,
+ _("%s is not logged in on %s"),
+ ctl.dst_login, ctl.dst_tty_name);
+ if (check_tty(ctl.dst_tty_path, &tty_writeable, NULL, 1))
+ exit(EXIT_FAILURE);
+ if (ctl.src_uid && !tty_writeable)
+ errx(EXIT_FAILURE,
+ _("%s has messages disabled on %s"),
+ ctl.dst_login, ctl.dst_tty_name);
+ do_write(&ctl);
+ break;
+ default:
+ errtryhelp(EXIT_FAILURE);
}
- return;
-#undef PUTC
+ free(ctl.dst_tty_path);
+ return EXIT_SUCCESS;
}
projects / thirdparty / util-linux.git / blobdiff