Commit | Line | Data |
---|---|---|
b40712b7 | 1 | static char *sccsid = "@(#)write.c 4.3 (Berkeley) %G%"; |
cd784246 BJ |
2 | /* |
3 | * write to another user | |
4 | */ | |
5 | ||
6 | #include <stdio.h> | |
7 | #include <sys/types.h> | |
8 | #include <sys/stat.h> | |
9 | #include <signal.h> | |
10 | #include <utmp.h> | |
11 | #include <time.h> | |
12 | ||
13 | #define NMAX sizeof(ubuf.ut_name) | |
14 | #define LMAX sizeof(ubuf.ut_line) | |
15 | ||
16 | char *strcat(); | |
17 | char *strcpy(); | |
18 | struct utmp ubuf; | |
19 | int signum[] = {SIGHUP, SIGINT, SIGQUIT, 0}; | |
20 | char me[10] = "???"; | |
21 | char *him; | |
22 | char *mytty; | |
23 | char histty[32]; | |
24 | char *histtya; | |
25 | char *ttyname(); | |
26 | char *rindex(); | |
27 | int logcnt; | |
28 | int eof(); | |
29 | int timout(); | |
30 | FILE *tf; | |
31 | char *getenv(); | |
32 | ||
33 | main(argc, argv) | |
34 | char *argv[]; | |
35 | { | |
36 | struct stat stbuf; | |
37 | register i; | |
38 | register FILE *uf; | |
39 | int c1, c2; | |
40 | long clock = time( 0 ); | |
41 | struct tm *localtime(); | |
42 | struct tm *localclock = localtime( &clock ); | |
43 | ||
44 | if(argc < 2) { | |
45 | printf("usage: write user [ttyname]\n"); | |
46 | exit(1); | |
47 | } | |
48 | him = argv[1]; | |
49 | if(argc > 2) | |
50 | histtya = argv[2]; | |
51 | if ((uf = fopen("/etc/utmp", "r")) == NULL) { | |
52 | printf("cannot open /etc/utmp\n"); | |
53 | goto cont; | |
54 | } | |
55 | mytty = ttyname(2); | |
56 | if (mytty == NULL) { | |
57 | printf("Can't find your tty\n"); | |
58 | exit(1); | |
59 | } | |
b40712b7 ES |
60 | if (stat (mytty, &stbuf) < 0) { |
61 | printf ("Can't stat your tty\n"); | |
62 | exit (1); | |
63 | } | |
64 | if ((stbuf.st_mode&02) == 0) { | |
65 | printf ("You have write permission turned off.\n"); | |
66 | exit (1); | |
67 | } | |
cd784246 BJ |
68 | mytty = rindex(mytty, '/') + 1; |
69 | if (histtya) { | |
70 | strcpy(histty, "/dev/"); | |
71 | strcat(histty, histtya); | |
72 | } | |
73 | while (fread((char *)&ubuf, sizeof(ubuf), 1, uf) == 1) { | |
b85a75a1 EA |
74 | if (ubuf.ut_name[0] == '\0') |
75 | continue; | |
cd784246 BJ |
76 | if (strcmp(ubuf.ut_line, mytty)==0) { |
77 | for(i=0; i<NMAX; i++) { | |
78 | c1 = ubuf.ut_name[i]; | |
79 | if(c1 == ' ') | |
80 | c1 = 0; | |
81 | me[i] = c1; | |
82 | if(c1 == 0) | |
83 | break; | |
84 | } | |
85 | } | |
86 | if(him[0] != '-' || him[1] != 0) | |
87 | for(i=0; i<NMAX; i++) { | |
88 | c1 = him[i]; | |
89 | c2 = ubuf.ut_name[i]; | |
90 | if(c1 == 0) | |
91 | if(c2 == 0 || c2 == ' ') | |
92 | break; | |
93 | if(c1 != c2) | |
94 | goto nomat; | |
95 | } | |
96 | logcnt++; | |
97 | if (histty[0]==0) { | |
98 | strcpy(histty, "/dev/"); | |
99 | strcat(histty, ubuf.ut_line); | |
100 | } | |
101 | nomat: | |
102 | ; | |
103 | } | |
104 | cont: | |
105 | if (logcnt==0 && histty[0]=='\0') { | |
106 | printf("%s not logged in.\n", him); | |
107 | exit(1); | |
108 | } | |
109 | fclose(uf); | |
110 | if (histtya==0 && logcnt > 1) { | |
111 | printf("%s logged more than once\nwriting to %s\n", him, histty+5); | |
112 | } | |
113 | if(histty[0] == 0) { | |
114 | printf(him); | |
115 | if(logcnt) | |
116 | printf(" not on that tty\n"); else | |
117 | printf(" not logged in\n"); | |
118 | exit(1); | |
119 | } | |
120 | if (access(histty, 0) < 0) { | |
121 | printf("No such tty\n"); | |
122 | exit(1); | |
123 | } | |
124 | signal(SIGALRM, timout); | |
125 | alarm(5); | |
126 | if ((tf = fopen(histty, "w")) == NULL) | |
127 | goto perm; | |
128 | alarm(0); | |
129 | if (fstat(fileno(tf), &stbuf) < 0) | |
130 | goto perm; | |
131 | if ((stbuf.st_mode&02) == 0) | |
132 | goto perm; | |
133 | sigs(eof); | |
134 | fprintf(tf, "\r\nMessage from "); | |
135 | #ifdef interdata | |
136 | fprintf(tf, "(Interdata) " ); | |
137 | #endif | |
138 | fprintf(tf, "%s on %s at %d:%02d ...\r\n\a\a\a" | |
139 | , me, mytty , localclock -> tm_hour , localclock -> tm_min ); | |
140 | fflush(tf); | |
141 | for(;;) { | |
142 | char buf[128]; | |
143 | i = read(0, buf, 128); | |
144 | if(i <= 0) | |
145 | eof(); | |
146 | if(buf[0] == '!') { | |
147 | buf[i] = 0; | |
148 | ex(buf); | |
149 | continue; | |
150 | } | |
151 | write(fileno(tf), buf, i); | |
152 | if ( buf[ i - 1 ] == '\n' ) | |
153 | write( fileno( tf ) , "\r" , 1 ); | |
154 | } | |
155 | ||
156 | perm: | |
157 | printf("Permission denied\n"); | |
158 | exit(1); | |
159 | } | |
160 | ||
161 | timout() | |
162 | { | |
163 | ||
164 | printf("Timeout opening their tty\n"); | |
165 | exit(1); | |
166 | } | |
167 | ||
168 | eof() | |
169 | { | |
170 | ||
171 | fprintf(tf, "EOF\r\n"); | |
172 | exit(0); | |
173 | } | |
174 | ||
175 | ex(bp) | |
176 | char *bp; | |
177 | { | |
178 | register i; | |
179 | ||
180 | sigs(SIG_IGN); | |
181 | i = fork(); | |
182 | if(i < 0) { | |
183 | printf("Try again\n"); | |
184 | goto out; | |
185 | } | |
186 | if(i == 0) { | |
187 | sigs((int (*)())0); | |
188 | execl(getenv("SHELL") ? getenv("SHELL") : "/bin/sh", "sh", "-c", bp+1, 0); | |
189 | exit(0); | |
190 | } | |
191 | while(wait((int *)NULL) != i) | |
192 | ; | |
193 | printf("!\n"); | |
194 | out: | |
195 | sigs(eof); | |
196 | } | |
197 | ||
198 | sigs(sig) | |
199 | int (*sig)(); | |
200 | { | |
201 | register i; | |
202 | ||
203 | for(i=0;signum[i];i++) | |
204 | signal(signum[i],sig); | |
205 | } |