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1 | /* |
2 | * Copyright (c) 1988 Mark Nudleman | |
3 | * Copyright (c) 1988 Regents of the University of California. | |
4 | * All rights reserved. | |
5 | * | |
6 | * This code is derived from software contributed to Berkeley by | |
7 | * Mark Nudleman. | |
8 | * | |
9 | * Redistribution and use in source and binary forms are permitted | |
10 | * provided that the above copyright notice and this paragraph are | |
11 | * duplicated in all such forms and that any documentation, | |
12 | * advertising materials, and other materials related to such | |
13 | * distribution and use acknowledge that the software was developed | |
14 | * by the University of California, Berkeley. The name of the | |
15 | * University may not be used to endorse or promote products derived | |
16 | * from this software without specific prior written permission. | |
17 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
18 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
19 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
20 | */ | |
21 | ||
22 | #ifndef lint | |
8e70b0c4 | 23 | static char sccsid[] = "@(#)os.c 5.5 (Berkeley) %G%"; |
bfe13c81 KB |
24 | #endif /* not lint */ |
25 | ||
26 | /* | |
27 | * Operating system dependent routines. | |
28 | * | |
29 | * Most of the stuff in here is based on Unix, but an attempt | |
30 | * has been made to make things work on other operating systems. | |
31 | * This will sometimes result in a loss of functionality, unless | |
32 | * someone rewrites code specifically for the new operating system. | |
33 | * | |
34 | * The makefile provides defines to decide whether various | |
35 | * Unix features are present. | |
36 | */ | |
37 | ||
38 | #include <stdio.h> | |
39 | #include <signal.h> | |
40 | #include <setjmp.h> | |
41 | #include "less.h" | |
42 | ||
43 | char *getenv(); | |
44 | ||
45 | public int reading; | |
46 | ||
47 | extern int screen_trashed; | |
48 | ||
49 | static jmp_buf read_label; | |
50 | ||
51 | /* | |
52 | * Pass the specified command to a shell to be executed. | |
53 | * Like plain "system()", but handles resetting terminal modes, etc. | |
54 | */ | |
55 | public void | |
56 | lsystem(cmd) | |
57 | char *cmd; | |
58 | { | |
59 | int inp; | |
60 | char cmdbuf[256]; | |
61 | char *shell; | |
62 | ||
63 | /* | |
64 | * Print the command which is to be executed, | |
65 | * unless the command starts with a "-". | |
66 | */ | |
67 | if (cmd[0] == '-') | |
68 | cmd++; | |
69 | else | |
70 | { | |
71 | lower_left(); | |
72 | clear_eol(); | |
73 | putstr("!"); | |
74 | putstr(cmd); | |
75 | putstr("\n"); | |
76 | } | |
77 | ||
78 | /* | |
79 | * De-initialize the terminal and take out of raw mode. | |
80 | */ | |
81 | deinit(); | |
82 | flush(); | |
83 | raw_mode(0); | |
84 | ||
85 | /* | |
86 | * Restore signals to their defaults. | |
87 | */ | |
88 | init_signals(0); | |
89 | ||
90 | /* | |
91 | * Force standard input to be the terminal, "/dev/tty", | |
92 | * even if less's standard input is coming from a pipe. | |
93 | */ | |
94 | inp = dup(0); | |
95 | close(0); | |
96 | if (open("/dev/tty", 0) < 0) | |
97 | dup(inp); | |
98 | ||
99 | /* | |
100 | * Pass the command to the system to be executed. | |
101 | * If we have a SHELL environment variable, use | |
102 | * <$SHELL -c "command"> instead of just <command>. | |
103 | * If the command is empty, just invoke a shell. | |
104 | */ | |
105 | if ((shell = getenv("SHELL")) != NULL && *shell != '\0') | |
106 | { | |
107 | if (*cmd == '\0') | |
108 | cmd = shell; | |
109 | else | |
110 | { | |
111 | sprintf(cmdbuf, "%s -c \"%s\"", shell, cmd); | |
112 | cmd = cmdbuf; | |
113 | } | |
114 | } | |
115 | if (*cmd == '\0') | |
116 | cmd = "sh"; | |
117 | ||
118 | system(cmd); | |
119 | ||
120 | /* | |
121 | * Restore standard input, reset signals, raw mode, etc. | |
122 | */ | |
123 | close(0); | |
124 | dup(inp); | |
125 | close(inp); | |
126 | ||
127 | init_signals(1); | |
128 | raw_mode(1); | |
129 | init(); | |
130 | screen_trashed = 1; | |
131 | #if defined(SIGWINCH) || defined(SIGWIND) | |
132 | /* | |
133 | * Since we were ignoring window change signals while we executed | |
134 | * the system command, we must assume the window changed. | |
135 | */ | |
136 | winch(); | |
137 | #endif | |
138 | } | |
139 | ||
140 | /* | |
141 | * Like read() system call, but is deliberately interruptable. | |
142 | * A call to intread() from a signal handler will interrupt | |
143 | * any pending iread(). | |
144 | */ | |
145 | public int | |
146 | iread(fd, buf, len) | |
147 | int fd; | |
148 | char *buf; | |
149 | int len; | |
150 | { | |
151 | register int n; | |
152 | ||
153 | if (setjmp(read_label)) | |
154 | /* | |
155 | * We jumped here from intread. | |
156 | */ | |
157 | return (READ_INTR); | |
158 | ||
159 | flush(); | |
160 | reading = 1; | |
161 | n = read(fd, buf, len); | |
162 | reading = 0; | |
163 | if (n < 0) | |
164 | return (-1); | |
165 | return (n); | |
166 | } | |
167 | ||
168 | public void | |
169 | intread() | |
170 | { | |
8e70b0c4 | 171 | sigsetmask(0L); |
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172 | longjmp(read_label, 1); |
173 | } | |
174 | ||
bfe13c81 KB |
175 | public long |
176 | get_time() | |
177 | { | |
54795006 | 178 | time_t time(); |
bfe13c81 | 179 | |
54795006 | 180 | return(time((long *)NULL)); |
bfe13c81 | 181 | } |
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182 | |
183 | /* | |
184 | * Expand a filename, substituting any environment variables, etc. | |
185 | * The implementation of this is necessarily very operating system | |
186 | * dependent. This implementation is unabashedly only for Unix systems. | |
187 | */ | |
188 | #if GLOB | |
189 | ||
190 | FILE *popen(); | |
191 | ||
192 | public char * | |
193 | glob(filename) | |
194 | char *filename; | |
195 | { | |
196 | FILE *f; | |
197 | char *p; | |
198 | int ch; | |
199 | char *cmd; | |
200 | static char buffer[FILENAME]; | |
201 | ||
202 | if (filename[0] == '#') | |
203 | return (filename); | |
204 | ||
205 | /* | |
206 | * We get the shell to expand the filename for us by passing | |
207 | * an "echo" command to the shell and reading its output. | |
208 | */ | |
209 | p = getenv("SHELL"); | |
210 | if (p == NULL || *p == '\0') | |
211 | { | |
212 | /* | |
213 | * Read the output of <echo filename>. | |
214 | */ | |
215 | cmd = calloc(strlen(filename)+8, sizeof(char)); | |
216 | if (cmd == NULL) | |
217 | return (filename); | |
218 | sprintf(cmd, "echo \"%s\"", filename); | |
219 | } else | |
220 | { | |
221 | /* | |
222 | * Read the output of <$SHELL -c "echo filename">. | |
223 | */ | |
224 | cmd = calloc(strlen(p)+12); | |
225 | if (cmd == NULL) | |
226 | return (filename); | |
227 | sprintf(cmd, "%s -c \"echo %s\"", p, filename); | |
228 | } | |
229 | ||
230 | if ((f = popen(cmd, "r")) == NULL) | |
231 | return (filename); | |
232 | free(cmd); | |
233 | ||
234 | for (p = buffer; p < &buffer[sizeof(buffer)-1]; p++) | |
235 | { | |
236 | if ((ch = getc(f)) == '\n' || ch == EOF) | |
237 | break; | |
238 | *p = ch; | |
239 | } | |
240 | *p = '\0'; | |
241 | pclose(f); | |
242 | return (buffer); | |
243 | } | |
244 | ||
245 | #else | |
246 | ||
247 | public char * | |
248 | glob(filename) | |
249 | char *filename; | |
250 | { | |
251 | return (filename); | |
252 | } | |
253 | ||
254 | #endif | |
255 | ||
256 | ||
257 | /* | |
258 | * Returns NULL if the file can be opened and | |
259 | * is an ordinary file, otherwise an error message | |
260 | * (if it cannot be opened or is a directory, etc.) | |
261 | */ | |
262 | ||
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263 | #include <sys/types.h> |
264 | #include <sys/stat.h> | |
265 | ||
266 | public char * | |
267 | bad_file(filename, message, len) | |
268 | char *filename; | |
269 | char *message; | |
270 | unsigned int len; | |
271 | { | |
272 | struct stat statbuf; | |
273 | ||
274 | if (stat(filename, &statbuf) < 0) | |
275 | return (errno_message(filename, message, len)); | |
276 | ||
277 | if ((statbuf.st_mode & S_IFMT) == S_IFDIR) | |
278 | { | |
279 | static char is_dir[] = " is a directory"; | |
280 | strtcpy(message, filename, len-sizeof(is_dir)-1); | |
281 | strcat(message, is_dir); | |
282 | return (message); | |
283 | } | |
284 | if ((statbuf.st_mode & S_IFMT) != S_IFREG) | |
285 | { | |
286 | static char not_reg[] = " is not a regular file"; | |
287 | strtcpy(message, filename, len-sizeof(not_reg)-1); | |
288 | strcat(message, not_reg); | |
289 | return (message); | |
290 | } | |
291 | return (NULL); | |
292 | } | |
293 | ||
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294 | /* |
295 | * errno_message: Return an error message based on the value of "errno". | |
296 | * okreadfail: Return true if the previous failure of a read | |
297 | * (on the input tty) should be considered ok. | |
298 | */ | |
299 | ||
bfe13c81 KB |
300 | extern char *sys_errlist[]; |
301 | extern int sys_nerr; | |
302 | extern int errno; | |
303 | ||
304 | public char * | |
305 | errno_message(filename, message, len) | |
306 | char *filename; | |
307 | char *message; | |
308 | unsigned int len; | |
309 | { | |
310 | char *p; | |
311 | char msg[16]; | |
312 | ||
313 | if (errno < sys_nerr) | |
314 | p = sys_errlist[errno]; | |
315 | else | |
316 | { | |
317 | sprintf(msg, "Error %d", errno); | |
318 | p = msg; | |
319 | } | |
320 | strtcpy(message, filename, len-strlen(p)-3); | |
321 | strcat(message, ": "); | |
322 | strcat(message, p); | |
323 | return (message); | |
324 | } |