Function docompress_file

src/files.c:1590–1775

* using system() is simpler, but opens up security holes and causes * problems on at least Interactive UNIX 3.0.1 (SVR3.2), where any * setuid is renounced by /bin/sh, so the files cannot be accessed. * * cf. child() in unixunix.c. */

 * cf. child() in unixunix.c.
 */
staticfn void
docompress_file(const char *filename, boolean uncomp)
{
    char *cfn = 0;
    const char *xtra;
    FILE *cf;
    const char *args[10];
#ifdef COMPRESS_OPTIONS
    char opts[sizeof COMPRESS_OPTIONS];
#endif
    int i = 0;
    int f, childstatus;
    unsigned ln;
#ifdef TTY_GRAPHICS
    boolean istty = WINDOWPORT(tty);
#endif

#ifdef COMPRESS_EXTENSION
    xtra = COMPRESS_EXTENSION;
#else
    xtra = "";
#endif
#ifdef SFCTOOL
    ln = strlen(filename) + sizeof COMPRESS_EXTENSION;
    cfn = (char *) alloc(ln);
#else /* SFCTOOL */
    ln = (unsigned) (strlen(filename) + strlen(xtra));
    cfn = (char *) alloc(ln + 1);
#endif /* SFCTOOL */

    Strcpy(cfn, filename);
    Strcat(cfn, xtra);

    /* when compressing, we know the file exists */
    if (uncomp) {
        if ((cf = fopen(cfn, RDBMODE)) == (FILE *) 0) {
            free((genericptr_t) cfn);
            return;
        }
        (void) fclose(cf);
    }

    args[0] = COMPRESS;
    if (uncomp)
        args[++i] = "-d"; /* uncompress */
#ifdef COMPRESS_OPTIONS
    {
        /* we can't guarantee there's only one additional option, sigh */
        char *opt;
        boolean inword = FALSE;

        opt = strcpy(opts, COMPRESS_OPTIONS);
        while (*opt) {
            if ((*opt == ' ') || (*opt == '\t')) {
                if (inword) {
                    *opt = '\0';
                    inword = FALSE;
                }