var.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
#include <ctype.h>
#include "ipf.h"
typedef struct variable {
struct variable *v_next;
char *v_name;
char *v_value;
} variable_t;
static variable_t *vtop = NULL;
static variable_t *find_var __P((char *));
static char *expand_string __P((char *, int));
static variable_t *find_var(name)
char *name;
{
variable_t *v;
for (v = vtop; v != NULL; v = v->v_next)
if (!strcmp(name, v->v_name))
return v;
return NULL;
}
char *get_variable(string, after, line)
char *string, **after;
int line;
{
char c, *s, *t, *value;
variable_t *v;
s = string;
if (*s == '{') {
s++;
for (t = s; *t != '\0'; t++)
if (*t == '}')
break;
if (*t == '\0') {
fprintf(stderr, "%d: { without }\n", line);
return NULL;
}
} else if (isalpha(*s)) {
for (t = s + 1; *t != '\0'; t++)
if (!isalpha(*t) && !isdigit(*t))
break;
} else {
fprintf(stderr, "%d: variables cannot start with '%c'\n",
line, *s);
return NULL;
}
if (after != NULL)
*after = t;
c = *t;
*t = '\0';
v = find_var(s);
*t = c;
if (v == NULL) {
fprintf(stderr, "%d: unknown variable '%s'\n", line, s);
return NULL;
}
s = strdup(v->v_value);
value = expand_string(s, line);
if (value != s)
free(s);
return value;
}
static char *expand_string(oldstring, line)
char *oldstring;
int line;
{
char c, *s, *p1, *p2, *p3, *newstring, *value;
int len;
p3 = NULL;
newstring = oldstring;
for (s = oldstring; *s != '\0'; s++)
if (*s == '$') {
*s = '\0';
s++;
switch (*s)
{
case '$' :
bcopy(s, s - 1, strlen(s));
break;
default :
c = *s;
value = get_variable(s, &p3, line);
if (value == NULL)
return NULL;
p2 = expand_string(value, line);
if (p2 == NULL)
return NULL;
len = strlen(newstring) + strlen(p2);
if (p3 != NULL) {
if (c == '{' && *p3 == '}')
p3++;
len += strlen(p3);
}
p1 = malloc(len + 1);
if (p1 == NULL)
return NULL;
*(s - 1) = '\0';
strcpy(p1, newstring);
strcat(p1, p2);
if (p3 != NULL)
strcat(p1, p3);
s = p1 + len - strlen(p3);
if (newstring != oldstring)
free(newstring);
newstring = p1;
break;
}
}
return newstring;
}
void set_variable(name, value)
char *name;
char *value;
{
variable_t *v;
int len;
if (name == NULL || value == NULL || *name == '\0')
return;
v = find_var(name);
if (v != NULL) {
free(v->v_value);
v->v_value = strdup(value);
return;
}
len = strlen(value);
if ((*value == '"' && value[len - 1] == '"') ||
(*value == '\'' && value[len - 1] == '\'')) {
value[len - 1] = '\0';
value++;
len -=2;
}
v = (variable_t *)malloc(sizeof(*v));
if (v == NULL)
return;
v->v_name = strdup(name);
v->v_value = strdup(value);
v->v_next = vtop;
vtop = v;
}