读取并分析wgetrc文件 2013-02-23 21:07 529人阅读 评论(0) 收藏

/* If the user did not specify a config, read the system wgetrc and ~/.wgetrc. */
if (use_userconfig == false)
initialize ();

/* Initialize the defaults and run the system wgetrc and user's own
wgetrc.  */
void
initialize (void)
{
char *file, *env_sysrc;
bool ok = true;

/* Run a non-standard system rc file when the according environment
variable has been set. For internal testing purposes only!  */
env_sysrc = getenv ("SYSTEM_WGETRC");
if (env_sysrc && file_exists_p (env_sysrc))
{
ok &= run_wgetrc (env_sysrc);
/* If there are any problems parsing the system wgetrc file, tell
the user and exit */
if (! ok)
{
fprintf (stderr, _("\
Parsing system wgetrc file (env SYSTEM_WGETRC) failed.  Please check\n\
'%s',\n\
or specify a different file using --config.\n"), env_sysrc);
exit (2);
}
}
/* Otherwise, if SYSTEM_WGETRC is defined, use it.  */
#ifdef SYSTEM_WGETRC
else if (file_exists_p (SYSTEM_WGETRC))
ok &= run_wgetrc (SYSTEM_WGETRC);
/* If there are any problems parsing the system wgetrc file, tell
the user and exit */
if (! ok)
{
fprintf (stderr, _("\
Parsing system wgetrc file failed.  Please check\n\
'%s',\n\
or specify a different file using --config.\n"), SYSTEM_WGETRC);
exit (2);
}
#endif
/* Override it with your own, if one exists.  */
file = wgetrc_file_name ();
if (!file)
return;
/* #### We should canonicalize `file' and SYSTEM_WGETRC with
something like realpath() before comparing them with `strcmp'  */
#ifdef SYSTEM_WGETRC
if (!strcmp (file, SYSTEM_WGETRC))
{
fprintf (stderr, _("\
%s: Warning: Both system and user wgetrc point to %s.\n"),
exec_name, quote (file));
}
else
#endif
ok &= run_wgetrc (file);

/* If there were errors processing either `.wgetrc', abort. */
if (!ok)
exit (2);

xfree (file);
return;
}

/* Initialize variables from a wgetrc file.  Returns zero (failure) if
there were errors in the file.  */

bool
run_wgetrc (const char *file)
{
FILE *fp;
char *line;
int ln;
int errcnt = 0;

fp = fopen (file, "r");
if (!fp)
{
fprintf (stderr, _("%s: Cannot read %s (%s).\n"), exec_name,
file, strerror (errno));
return true;                      /* not a fatal error */
}
ln = 1;
while ((line = read_whole_line (fp)) != NULL)
{
char *com = NULL, *val = NULL;
int comind;

/* Parse the line.  */
switch (parse_line (line, &com, &val, &comind))
{
case line_ok:
/* If everything is OK, set the value.  */
if (!setval_internal_tilde (comind, com, val))
{
fprintf (stderr, _("%s: Error in %s at line %d.\n"),
exec_name, file, ln);
++errcnt;
}
break;
case line_syntax_error:
fprintf (stderr, _("%s: Syntax error in %s at line %d.\n"),
exec_name, file, ln);
++errcnt;
break;
case line_unknown_command:
fprintf (stderr, _("%s: Unknown command %s in %s at line %d.\n"),
exec_name, quote (com), file, ln);
++errcnt;
break;
case line_empty:
break;
default:
abort ();
}
xfree_null (com);
xfree_null (val);
xfree (line);
++ln;
}
fclose (fp);

return errcnt == 0;
}

static enum parse_line
parse_line (const char *line, char **com, char **val, int *comind)
{
const char *p;
const char *end = line + strlen (line);
const char *cmdstart, *cmdend;
const char *valstart, *valend;

char *cmdcopy;
int ind;

/* Skip leading and trailing whitespace.  */
while (*line && c_isspace (*line))
++line;
while (end > line && c_isspace (end[-1]))
--end;

/* Skip empty lines and comments.  */
if (!*line || *line == '#')
return line_empty;

p = line;

cmdstart = p;
while (p < end && (c_isalnum (*p) || *p == '_' || *p == '-'))
++p;
cmdend = p;

/* Skip '=', as well as any space before or after it. */
while (p < end && c_isspace (*p))
++p;
if (p == end || *p != '=')
return line_syntax_error;
++p;
while (p < end && c_isspace (*p))
++p;

valstart = p;
valend   = end;

/* The syntax is valid (even though the command might not be).  Fill
in the command name and value.  */
*com = strdupdelim (cmdstart, cmdend);
*val = strdupdelim (valstart, valend);

/* The line now known to be syntactically correct.  Check whether
the command is valid.  */
BOUNDED_TO_ALLOCA (cmdstart, cmdend, cmdcopy);
dehyphen (cmdcopy);
ind = command_by_name (cmdcopy);
if (ind == -1)
return line_unknown_command;

/* Report success to the caller. */
*comind = ind;
return line_ok;
}