101 lines
1.7 KiB
C
101 lines
1.7 KiB
C
/*
|
|
* Expand a string, substituting any "%" with the current filename,
|
|
* and any "#" with the previous filename and an initial "!" with
|
|
* the second string.
|
|
*/
|
|
char *
|
|
fexpand(s, t)
|
|
char *s;
|
|
char *t;
|
|
{
|
|
extern char *current_file, *previous_file;
|
|
register char *fr, *to;
|
|
register int n;
|
|
register char *e;
|
|
|
|
if (*s == '\0')
|
|
return ((char *) 0);
|
|
/*
|
|
* Make one pass to see how big a buffer we
|
|
* need to allocate for the expanded string.
|
|
*/
|
|
n = 0;
|
|
for (fr = s; *fr != '\0'; fr++)
|
|
{
|
|
switch (*fr)
|
|
{
|
|
case '!':
|
|
if (s == fr && t == (char *) 0) {
|
|
error("no previous command");
|
|
return ((char *) 0);
|
|
}
|
|
n += (s == fr) ? strlen(t) : 1;
|
|
break;
|
|
case '%':
|
|
n += (current_file != (char *) 0) ?
|
|
strlen(current_file) : 1;
|
|
break;
|
|
case '#':
|
|
n += (previous_file != (char *) 0) ?
|
|
strlen(previous_file) : 1;
|
|
break;
|
|
default:
|
|
n++;
|
|
if (*fr == '\\') {
|
|
n++;
|
|
if (*++fr == '\0') {
|
|
error("syntax error");
|
|
return ((char *) 0);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
if ((e = (char *) calloc(n+1, sizeof(char))) == (char *) 0) {
|
|
error("cannot allocate memory");
|
|
quit();
|
|
}
|
|
|
|
/*
|
|
* Now copy the string, expanding any "%" or "#".
|
|
*/
|
|
to = e;
|
|
for (fr = s; *fr != '\0'; fr++)
|
|
{
|
|
switch (*fr)
|
|
{
|
|
case '!':
|
|
if (s == fr) {
|
|
strcpy(to, t);
|
|
to += strlen(to);
|
|
} else
|
|
*to++ = *fr;
|
|
break;
|
|
case '%':
|
|
if (current_file == (char *) 0)
|
|
*to++ = *fr;
|
|
else {
|
|
strcpy(to, current_file);
|
|
to += strlen(to);
|
|
}
|
|
break;
|
|
case '#':
|
|
if (previous_file == (char *) 0)
|
|
*to++ = *fr;
|
|
else {
|
|
strcpy(to, previous_file);
|
|
to += strlen(to);
|
|
}
|
|
break;
|
|
default:
|
|
*to++ = *fr;
|
|
if (*fr == '\\')
|
|
*to++ = *++fr;
|
|
break;
|
|
}
|
|
}
|
|
*to = '\0';
|
|
return (e);
|
|
}
|