help.c revision e0ed7404719a9ddd2ba427a80db5365c8bad18c0 
1/*
2 * Copyright 1987, 1988 by MIT Student Information Processing Board
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose is hereby granted, provided that
6 * the names of M.I.T. and the M.I.T. S.I.P.B. not be used in
7 * advertising or publicity pertaining to distribution of the software
8 * without specific, written prior permission.  M.I.T. and the
9 * M.I.T. S.I.P.B. make no representations about the suitability of
10 * this software for any purpose.  It is provided "as is" without
11 * express or implied warranty.
12 */
13
14#ifdef HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#ifdef HAVE_STDLIB_H
18#include <stdlib.h>
19#endif
20#ifdef HAVE_ERRNO_H
21#include <errno.h>
22#else
23extern int errno;
24#endif
25#include <fcntl.h>
26#include <sys/param.h>
27#include <sys/types.h>
28#include <sys/file.h>
29#ifdef NEED_SYS_FCNTL_H
30/* just for O_* */
31#include <sys/fcntl.h>
32#endif
33#ifdef HAVE_SYS_WAIT_H
34#include <sys/wait.h>
35#endif
36#include "ss_internal.h"
37
38void ss_help(int argc, char const * const *argv, int sci_idx, pointer info_ptr)
39{
40    char *buffer;
41    char const *request_name;
42    int code;
43    int fd, child;
44    register int idx;
45    register ss_data *info;
46
47    request_name = ss_current_request(sci_idx, &code);
48    if (code != 0) {
49	ss_perror(sci_idx, code, "");
50	return;		/* no ss_abort_line, if invalid invocation */
51    }
52    if (argc == 1) {
53	ss_list_requests(argc, argv, sci_idx, info_ptr);
54	return;
55    }
56    else if (argc != 2) {
57	/* should do something better than this */
58	buffer = malloc(80+2*strlen(request_name));
59	if (!buffer) {
60		ss_perror(sci_idx, 0,
61			  "couldn't allocate memory to print usage message");
62		return;
63	}
64	sprintf(buffer, "usage:\n\t%s [topic|command]\nor\t%s\n",
65		request_name, request_name);
66	ss_perror(sci_idx, 0, buffer);
67	free(buffer);
68	return;
69    }
70    info = ss_info(sci_idx);
71    if (info->info_dirs == (char **)NULL) {
72	ss_perror(sci_idx, SS_ET_NO_INFO_DIR, (char *)NULL);
73	return;
74    }
75    if (info->info_dirs[0] == (char *)NULL) {
76	ss_perror(sci_idx, SS_ET_NO_INFO_DIR, (char *)NULL);
77	return;
78    }
79    for (fd = -1, idx = 0; info->info_dirs[idx] != (char *)NULL; idx++) {
80        buffer = malloc(strlen (info->info_dirs[idx]) + 1 +
81			strlen (argv[1]) + 6);
82	if (!buffer) {
83	    ss_perror(sci_idx, 0,
84		      "couldn't allocate memory for help filename");
85	    return;
86	}
87	(void) strcpy(buffer, info->info_dirs[idx]);
88	(void) strcat(buffer, "/");
89	(void) strcat(buffer, argv[1]);
90	(void) strcat(buffer, ".info");
91	fd = open(buffer, O_RDONLY);
92	free(buffer);
93	if (fd >= 0)
94	    break;
95    }
96    if (fd < 0) {
97#define MSG "No info found for "
98        char *buf = malloc(strlen (MSG) + strlen (argv[1]) + 1);
99	strcpy(buf, MSG);
100	strcat(buf, argv[1]);
101	ss_perror(sci_idx, 0, buf);
102	free(buf);
103	return;
104    }
105    switch (child = fork()) {
106    case -1:
107	ss_perror(sci_idx, errno, "Can't fork for pager");
108	(void) close(fd);
109	return;
110    case 0:
111	(void) dup2(fd, 0); /* put file on stdin */
112	ss_page_stdin();
113    default:
114	(void) close(fd); /* what can we do if it fails? */
115	while (wait(NULL) != child) {
116	    /* do nothing if wrong pid */
117	};
118    }
119}
120
121#ifndef HAVE_DIRENT_H
122#include <sys/dir.h>
123#else
124#include <dirent.h>
125#endif
126
127void ss_add_info_dir(int sci_idx, char *info_dir, int *code_ptr)
128{
129    register ss_data *info;
130    DIR *d;
131    int n_dirs;
132    register char **dirs;
133
134    info = ss_info(sci_idx);
135    if (info_dir == NULL || *info_dir == '\0') {
136	*code_ptr = SS_ET_NO_INFO_DIR;
137	return;
138    }
139    if ((d = opendir(info_dir)) == (DIR *)NULL) {
140	*code_ptr = errno;
141	return;
142    }
143    closedir(d);
144    dirs = info->info_dirs;
145    for (n_dirs = 0; dirs[n_dirs] != (char *)NULL; n_dirs++)
146	;		/* get number of non-NULL dir entries */
147    dirs = (char **)realloc((char *)dirs,
148			    (unsigned)(n_dirs + 2)*sizeof(char *));
149    if (dirs == (char **)NULL) {
150	info->info_dirs = (char **)NULL;
151	*code_ptr = errno;
152	return;
153    }
154    info->info_dirs = dirs;
155    dirs[n_dirs + 1] = (char *)NULL;
156    dirs[n_dirs] = malloc((unsigned)strlen(info_dir)+1);
157    strcpy(dirs[n_dirs], info_dir);
158    *code_ptr = 0;
159}
160
161void ss_delete_info_dir(int sci_idx, char *info_dir, int *code_ptr)
162{
163    register char **i_d;
164    register char **info_dirs;
165
166    info_dirs = ss_info(sci_idx)->info_dirs;
167    for (i_d = info_dirs; *i_d; i_d++) {
168	if (!strcmp(*i_d, info_dir)) {
169	    while (*i_d) {
170		*i_d = *(i_d+1);
171		i_d++;
172	    }
173	    *code_ptr = 0;
174	    return;
175	}
176    }
177    *code_ptr = SS_ET_NO_INFO_DIR;
178}
179