Commit | Line | Data |
---|---|---|
dd6edb81 BJ |
1 | /* |
2 | * write to another user | |
3 | */ | |
4 | ||
5 | #include <stdio.h> | |
6 | #include <sys/types.h> | |
7 | #include <sys/stat.h> | |
8 | #include <signal.h> | |
9 | #include <utmp.h> | |
10 | #include <time.h> | |
11 | ||
12 | char *strcat(); | |
13 | char *strcpy(); | |
14 | struct utmp ubuf; | |
15 | int signum[] = {SIGHUP, SIGINT, SIGQUIT, 0}; | |
16 | char me[10] = "???"; | |
17 | char *him; | |
18 | char *mytty; | |
19 | char histty[32]; | |
20 | char *histtya; | |
21 | char *ttyname(); | |
22 | char *rindex(); | |
23 | int logcnt; | |
24 | int eof(); | |
25 | int timout(); | |
26 | FILE *tf; | |
27 | char *getenv(); | |
28 | ||
29 | main(argc, argv) | |
30 | char *argv[]; | |
31 | { | |
32 | struct stat stbuf; | |
33 | register i; | |
34 | register FILE *uf; | |
35 | int c1, c2; | |
36 | long clock = time( 0 ); | |
37 | struct tm *localtime(); | |
38 | struct tm *localclock = localtime( &clock ); | |
39 | ||
40 | if(argc < 2) { | |
41 | printf("usage: write user [ttyname]\n"); | |
42 | exit(1); | |
43 | } | |
44 | him = argv[1]; | |
45 | if(argc > 2) | |
46 | histtya = argv[2]; | |
47 | if ((uf = fopen("/etc/utmp", "r")) == NULL) { | |
48 | printf("cannot open /etc/utmp\n"); | |
49 | goto cont; | |
50 | } | |
51 | mytty = ttyname(2); | |
52 | if (mytty == NULL) { | |
53 | printf("Can't find your tty\n"); | |
54 | exit(1); | |
55 | } | |
56 | mytty = rindex(mytty, '/') + 1; | |
57 | if (histtya) { | |
58 | strcpy(histty, "/dev/"); | |
59 | strcat(histty, histtya); | |
60 | } | |
61 | while (fread((char *)&ubuf, sizeof(ubuf), 1, uf) == 1) { | |
62 | if (strcmp(ubuf.ut_line, mytty)==0) { | |
63 | for(i=0; i<8; i++) { | |
64 | c1 = ubuf.ut_name[i]; | |
65 | if(c1 == ' ') | |
66 | c1 = 0; | |
67 | me[i] = c1; | |
68 | if(c1 == 0) | |
69 | break; | |
70 | } | |
71 | } | |
72 | if(him[0] != '-' || him[1] != 0) | |
73 | for(i=0; i<8; i++) { | |
74 | c1 = him[i]; | |
75 | c2 = ubuf.ut_name[i]; | |
76 | if(c1 == 0) | |
77 | if(c2 == 0 || c2 == ' ') | |
78 | break; | |
79 | if(c1 != c2) | |
80 | goto nomat; | |
81 | } | |
82 | logcnt++; | |
83 | if (histty[0]==0) { | |
84 | strcpy(histty, "/dev/"); | |
85 | strcat(histty, ubuf.ut_line); | |
86 | } | |
87 | nomat: | |
88 | ; | |
89 | } | |
90 | cont: | |
91 | if (logcnt==0 && histty[0]=='\0') { | |
92 | printf("%s not logged in.\n", him); | |
93 | exit(1); | |
94 | } | |
95 | fclose(uf); | |
96 | if (histtya==0 && logcnt > 1) { | |
97 | printf("%s logged more than once\nwriting to %s\n", him, histty+5); | |
98 | } | |
99 | if(histty[0] == 0) { | |
100 | printf(him); | |
101 | if(logcnt) | |
102 | printf(" not on that tty\n"); else | |
103 | printf(" not logged in\n"); | |
104 | exit(1); | |
105 | } | |
106 | if (access(histty, 0) < 0) { | |
107 | printf("No such tty\n"); | |
108 | exit(1); | |
109 | } | |
110 | signal(SIGALRM, timout); | |
111 | alarm(5); | |
112 | if ((tf = fopen(histty, "w")) == NULL) | |
113 | goto perm; | |
114 | alarm(0); | |
115 | if (fstat(fileno(tf), &stbuf) < 0) | |
116 | goto perm; | |
117 | if ((stbuf.st_mode&02) == 0) | |
118 | goto perm; | |
119 | sigs(eof); | |
120 | fprintf(tf, "\r\nMessage from "); | |
121 | #ifdef interdata | |
122 | fprintf(tf, "(Interdata) " ); | |
123 | #endif | |
124 | fprintf(tf, "%s on %s at %d:%02d ...\r\n\a\a\a" | |
125 | , me, mytty , localclock -> tm_hour , localclock -> tm_min ); | |
126 | fflush(tf); | |
127 | for(;;) { | |
128 | char buf[128]; | |
129 | i = read(0, buf, 128); | |
130 | if(i <= 0) | |
131 | eof(); | |
132 | if(buf[0] == '!') { | |
133 | buf[i] = 0; | |
134 | ex(buf); | |
135 | continue; | |
136 | } | |
137 | write(fileno(tf), buf, i); | |
138 | if ( buf[ i - 1 ] == '\n' ) | |
139 | write( fileno( tf ) , "\r" , 1 ); | |
140 | } | |
141 | ||
142 | perm: | |
143 | printf("Permission denied\n"); | |
144 | exit(1); | |
145 | } | |
146 | ||
147 | timout() | |
148 | { | |
149 | ||
150 | printf("Timeout opening their tty\n"); | |
151 | exit(1); | |
152 | } | |
153 | ||
154 | eof() | |
155 | { | |
156 | ||
157 | fprintf(tf, "EOF\r\n"); | |
158 | exit(0); | |
159 | } | |
160 | ||
161 | ex(bp) | |
162 | char *bp; | |
163 | { | |
164 | register i; | |
165 | ||
166 | sigs(SIG_IGN); | |
167 | i = fork(); | |
168 | if(i < 0) { | |
169 | printf("Try again\n"); | |
170 | goto out; | |
171 | } | |
172 | if(i == 0) { | |
173 | sigs((int (*)())0); | |
174 | execl(getenv("SHELL") ? getenv("SHELL") : "/bin/sh", "sh", "-c", bp+1, 0); | |
175 | exit(0); | |
176 | } | |
177 | while(wait((int *)NULL) != i) | |
178 | ; | |
179 | printf("!\n"); | |
180 | out: | |
181 | sigs(eof); | |
182 | } | |
183 | ||
184 | sigs(sig) | |
185 | int (*sig)(); | |
186 | { | |
187 | register i; | |
188 | ||
189 | for(i=0;signum[i];i++) | |
190 | signal(signum[i],sig); | |
191 | } |