added substitute_shell_vars and shell_var_value functions.

git-svn-id: svn+ssh://rpmlint.zarb.org/home/projects/rpmlint/svn/trunk@577 9bc8b190-ac0f-0410-8968-dc7d1f502856

Pkg.py

@@ -34,6 +34,8 @@ try:
 except AttributeError:
     v304=0
 
+# utilities
+
 def grep(regex, filename):
     fd=open(filename, "r")
     ret=0
@@ -49,6 +51,28 @@ def grep(regex, filename):
         print "unable to open", filename
     return ret
 
+def shell_var_value(var, script):
+    assign_regex=re.compile(var + '\s*=\s*(.+)\s*(#.*)*$', re.MULTILINE)
+    res=assign_regex.search(script)
+    if res:
+        return substitute_shell_vars(res.group(1), script)
+    else:
+        return None
+
+var_regex=re.compile('^(.*)\${?([^}]+)}?(.*)$')
+
+def substitute_shell_vars(val, script):
+    res=var_regex.search(val)
+    if res:
+        value=shell_var_value(res.group(2), script)
+        if not value:
+            value=''
+        return res.group(1) + value + substitute_shell_vars(res.group(3), script)
+    else:
+        return val
+
+# classes representing package
+
 class Pkg:
     file_regex=re.compile("(?:\.)?([^:]+):\s+(.*)")