help.c

/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 * Copyright 1987, 1988 by MIT Student Information Processing Board
 *
 * For copyright info, see copyright.h.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <errno.h>
#include <sys/file.h>
#include <fcntl.h>      /* just for O_* */
#include <sys/wait.h>
#include "ss_internal.h"
#include "copyright.h"


void
ss_help(int argc, char const * const *argv, int sci_idx, pointer info_ptr)
{
    char buffer[MAXPATHLEN];
    char const *request_name;
    int code;
    int fd, child;
    int idx;
    ss_data *info;

    request_name = ss_current_request(sci_idx, &code);
    if (code != 0) {
        ss_perror(sci_idx, code, "");
        return;         /* no ss_abort_line, if invalid invocation */
    }
    if (argc == 1) {
        ss_list_requests(argc, argv, sci_idx, info_ptr);
        return;
    }
    else if (argc != 2) {
        /* should do something better than this */
        snprintf(buffer, sizeof(buffer),
                 "usage:\n\t%s [topic|command]\nor\t%s\n",
                 request_name, request_name);
        ss_perror(sci_idx, 0, buffer);
        return;
    }
    info = ss_info(sci_idx);
    if (info->info_dirs == (char **)NULL) {
        ss_perror(sci_idx, SS_ET_NO_INFO_DIR, (char *)NULL);
        return;
    }
    if (info->info_dirs[0] == (char *)NULL) {
        ss_perror(sci_idx, SS_ET_NO_INFO_DIR, (char *)NULL);
        return;
    }
    for (idx = 0; info->info_dirs[idx] != (char *)NULL; idx++) {
        (void) strncpy(buffer, info->info_dirs[idx], sizeof(buffer) - 1);
        buffer[sizeof(buffer) - 1] = '\0';
        (void) strncat(buffer, "/", sizeof(buffer) - 1 - strlen(buffer));
        (void) strncat(buffer, argv[1], sizeof(buffer) - 1 - strlen(buffer));
        (void) strncat(buffer, ".info", sizeof(buffer) - 1 - strlen(buffer));
        if ((fd = open(&buffer[0], O_RDONLY)) >= 0) goto got_it;
    }
    if ((fd = open(&buffer[0], O_RDONLY)) < 0) {
        char buf[MAXPATHLEN];
        strncpy(buf, "No info found for ", sizeof(buf) - 1);
        buf[sizeof(buf) - 1] = '\0';
        strncat(buf, argv[1], sizeof(buf) - 1 - strlen(buf));
        ss_perror(sci_idx, 0, buf);
        return;
    }
got_it:
    switch (child = fork()) {
    case -1:
        ss_perror(sci_idx, errno, "Can't fork for pager");
        close(fd);
        return;
    case 0:
        (void) dup2(fd, 0); /* put file on stdin */
        ss_page_stdin();
    default:
        (void) close(fd); /* what can we do if it fails? */
        while (wait(NULL) != child) {
            /* do nothing if wrong pid */
        };
    }
}

#ifndef USE_DIRENT_H
#include <sys/dir.h>
#else
#include <dirent.h>
#endif

void
ss_add_info_dir(int sci_idx, char *info_dir, int *code_ptr)
{
    ss_data *info;
    DIR *d;
    int n_dirs;
    char **dirs;

    info = ss_info(sci_idx);
    if ((info_dir == NULL) || (*info_dir == '\0')) {
        *code_ptr = SS_ET_NO_INFO_DIR;
        return;
    }
    if ((d = opendir(info_dir)) == (DIR *)NULL) {
        *code_ptr = errno;
        return;
    }
    closedir(d);
    dirs = info->info_dirs;
    for (n_dirs = 0; dirs[n_dirs] != (char *)NULL; n_dirs++)
        ;               /* get number of non-NULL dir entries */
    dirs = (char **)realloc((char *)dirs,
                            (unsigned)(n_dirs + 2)*sizeof(char *));
    if (dirs == (char **)NULL) {
        info->info_dirs = (char **)NULL;
        *code_ptr = errno;
        return;
    }
    info->info_dirs = dirs;
    dirs[n_dirs + 1] = (char *)NULL;
    dirs[n_dirs] = strdup(info_dir);
    *code_ptr = 0;
}

void
ss_delete_info_dir(int sci_idx, char *info_dir, int *code_ptr)
{
    char **i_d;
    char **info_dirs;

    info_dirs = ss_info(sci_idx)->info_dirs;
    for (i_d = info_dirs; *i_d; i_d++) {
        if (!strcmp(*i_d, info_dir)) {
            while (*i_d) {
                *i_d = *(i_d+1);
                i_d++;
            }
            *code_ptr = 0;
            return;
        }
    }
    *code_ptr = SS_ET_NO_INFO_DIR;
}