From 5fd83771641d15c418f747bd343ba6738d3875f7 Mon Sep 17 00:00:00 2001 From: Cameron Katri Date: Sun, 9 May 2021 14:20:58 -0400 Subject: Import macOS userland adv_cmds-176 basic_cmds-55 bootstrap_cmds-116.100.1 developer_cmds-66 diskdev_cmds-667.40.1 doc_cmds-53.60.1 file_cmds-321.40.3 mail_cmds-35 misc_cmds-34 network_cmds-606.40.1 patch_cmds-17 remote_cmds-63 shell_cmds-216.60.1 system_cmds-880.60.2 text_cmds-106 --- basic_cmds/write/write.c | 332 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 332 insertions(+) create mode 100644 basic_cmds/write/write.c (limited to 'basic_cmds/write/write.c') diff --git a/basic_cmds/write/write.c b/basic_cmds/write/write.c new file mode 100644 index 0000000..e3f2255 --- /dev/null +++ b/basic_cmds/write/write.c @@ -0,0 +1,332 @@ +/* + * Copyright (c) 1989, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include +#ifndef lint +__unused static const char copyright[] = +"@(#) Copyright (c) 1989, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif + +#if 0 +#ifndef lint +static char sccsid[] = "@(#)write.c 8.1 (Berkeley) 6/6/93"; +#endif +#endif + +__RCSID("$FreeBSD: src/usr.bin/write/write.c,v 1.17 2002/09/04 23:29:09 dwmalone Exp $"); + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +void done(int); +void do_write(char *, char *, uid_t); +static void usage(void); +int term_chk(char *, int *, time_t *, int); +void wr_fputs(unsigned char *s); +void search_utmp(char *, char *, char *, uid_t); +int utmp_chk(char *, char *); + +int +main(int argc, char **argv) +{ + char *cp; + time_t atime; + uid_t myuid; + int msgsok, myttyfd; + char tty[MAXPATHLEN], *mytty; + + (void)setlocale(LC_CTYPE, ""); + + while (getopt(argc, argv, "") != -1) + usage(); + argc -= optind; + argv += optind; + + /* 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) + mytty = "tty??"; + else + { + if (!(mytty = ttyname(myttyfd))) + errx(1, "can't find your tty's name"); + if ((cp = rindex(mytty, '/'))) + mytty = cp + 1; + if (term_chk(mytty, &msgsok, &atime, 1)) + exit(1); + if (!msgsok) + errx(1, "you have write permission turned off"); + } + myuid = getuid(); + + /* check args */ + switch (argc) { + case 1: + search_utmp(argv[0], tty, mytty, myuid); + do_write(tty, mytty, myuid); + break; + case 2: + if (!strncmp(argv[1], _PATH_DEV, strlen(_PATH_DEV))) + argv[1] += strlen(_PATH_DEV); + if (utmp_chk(argv[0], argv[1])) + errx(1, "%s is not logged in on %s", argv[0], argv[1]); + if (term_chk(argv[1], &msgsok, &atime, 1)) + exit(1); + if (myuid && !msgsok) + errx(1, "%s has messages disabled on %s", argv[0], argv[1]); + do_write(argv[1], mytty, myuid); + break; + default: + usage(); + } + done(0); + return (0); +} + +static void +usage(void) +{ + (void)fprintf(stderr, "usage: write user [tty]\n"); + exit(1); +} + +/* + * utmp_chk - checks that the given user is actually logged in on + * the given tty + */ +int +utmp_chk(char *user, char *tty) +{ + struct utmpx *u; + + setutxent(); + while((u = getutxent()) != NULL) + if(strncmp(u->ut_line, tty, sizeof(u->ut_line)) == 0) { + if(u->ut_type == USER_PROCESS && + strncmp(u->ut_user, user, sizeof(u->ut_user)) == 0) { + endutxent(); + return 0; + } + break; + } + endutxent(); + return 1; +} + +/* + * search_utmp - search utmp for the "best" terminal to write to + * + * Ignores terminals with messages disabled, and of the rest, returns + * the one with the most recent access time. Returns as value the number + * of the user's terminals with messages enabled, or -1 if the user is + * not logged in at all. + * + * 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) +{ + struct utmpx ux, *u; + time_t bestatime, atime; + int nloggedttys, nttys, msgsok, user_is_me; + char atty[sizeof(ux.ut_line) + 1]; + + nloggedttys = nttys = 0; + bestatime = 0; + user_is_me = 0; + setutxent(); + while ((u = getutxent()) != NULL) { + if (u->ut_type != USER_PROCESS) + continue; + if (strncmp(user, u->ut_user, sizeof(u->ut_user)) == 0) { + ++nloggedttys; + (void)strlcpy(atty, u->ut_line, sizeof(atty)); + if (term_chk(atty, &msgsok, &atime, 0)) + continue; /* bad term? skip */ + if (myuid && !msgsok) + continue; /* skip ttys with msgs off */ + if (strcmp(atty, mytty) == 0) { + user_is_me = 1; + continue; /* don't write to yourself */ + } + ++nttys; + if (atime > bestatime) { + bestatime = atime; + (void)strcpy(tty, atty); + } + } + } + + endutxent(); + if (nloggedttys == 0) + errx(1, "%s is not logged in", user); + if (nttys == 0) { + if (user_is_me) { /* ok, so write to yourself! */ + (void)strcpy(tty, mytty); + return; + } + errx(1, "%s has messages disabled", user); + } else if (nttys > 1) { + warnx("%s is logged in more than once; writing to %s", user, tty); + } +} + +/* + * term_chk - check that a terminal exists, and get the message bit + * and the access time + */ +int +term_chk(char *tty, int *msgsokP, time_t *atimeP, int showerror) +{ + struct stat s; + char path[MAXPATHLEN]; + + (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty); + if (stat(path, &s) < 0) { + if (showerror) + warn("%s", path); + return(1); + } + *msgsokP = (s.st_mode & (S_IWRITE >> 3)) != 0; /* group write bit */ + *atimeP = s.st_atime; + return(0); +} + +/* + * do_write - actually make the connection + */ +void +do_write(char *tty, char *mytty, uid_t myuid) +{ + const char *login; + char *nows; + struct passwd *pwd; + time_t now; + char path[MAXPATHLEN], host[MAXHOSTNAMELEN], line[512]; + + /* Determine our login name before the we reopen() stdout */ + if ((login = getlogin()) == NULL) { + if ((pwd = getpwuid(myuid))) + login = pwd->pw_name; + else + login = "???"; + } + + (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty); + if ((freopen(path, "w", stdout)) == NULL) + err(1, "%s", path); + + (void)signal(SIGINT, done); + (void)signal(SIGHUP, done); + + /* print greeting */ + if (gethostname(host, sizeof(host)) < 0) + (void)strcpy(host, "???"); + now = time((time_t *)NULL); + nows = ctime(&now); + nows[16] = '\0'; + (void)printf("\r\n\007\007\007Message from %s@%s on %s at %s ...\r\n", + login, host, mytty, nows + 11); + + while (fgets(line, sizeof(line), stdin) != NULL) + wr_fputs((unsigned char *)line); +} + +/* + * done - cleanup and exit + */ +void +done(int n) +{ + (void)printf("EOF\r\n"); + exit(0); +} + +/* + * wr_fputs - like fputs(), but makes control characters visible and + * turns \n into \r\n + */ +void +wr_fputs(unsigned char *s) +{ + +#define PUTC(c) if (putchar(c) == EOF) err(1, NULL); + + for (; *s != '\0'; ++s) { + if (*s == '\n') { + PUTC('\r'); + } else if (((*s & 0x80) && *s < 0xA0) || + /* disable upper controls */ + (!isprint(*s) && !isspace(*s) && + *s != '\a' && *s != '\b') + ) { + if (*s & 0x80) { + *s &= ~0x80; + PUTC('M'); + PUTC('-'); + } + if (iscntrl(*s)) { + *s ^= 0x40; + PUTC('^'); + } + } + PUTC(*s); + } + return; +#undef PUTC +} -- cgit v1.2.3-56-ge451