lexer: Add shell commands with %(echo 123..).

It is possible to use shell commands, just like $(...) in shell.
It's a handy feature when you need some output of a tool
in a variable.

Every time the variable is expanded, the command is called.
It is not ensured that the personality is the same as in
the build environment.

diff --git a/python/pakfire/packages/lexer.py b/python/pakfire/packages/lexer.py
index 09a8215eb099adcb2ecf8233f16c12bc701f9bfc..af6dda0fdbe56f8853fe4c8f4d2b116e33abccf0 100644 (file)
--- a/python/pakfire/packages/lexer.py
+++ b/python/pakfire/packages/lexer.py
@@ -6,6 +6,8 @@ import re
 from pakfire.constants import *
 from pakfire.i18n import _
 
+import pakfire.chroot
+
 import logging
 #log = logging.getLogger("pakfire.lexer")
 log = logging.getLogger("pakfire")
@@ -90,7 +92,7 @@ LEXER_UNEXPORT        = re.compile(r"^unexport\s+([A-Za-z0-9_\-]+)$")
 LEXER_INCLUDE         = re.compile(r"^include\s+(.+)$")
 
 LEXER_VARIABLE        = re.compile(r"\%\{([A-Za-z0-9_\-]+)\}")
-LEXER_SHELL           = re.compile(r"\%\(.*\)")
+LEXER_SHELL           = re.compile(r"\%\((.*)\)")
 
 LEXER_IF_IF           = re.compile(r"^if\s+(.*)\s+(==|!=)\s+(.*)\s*")
 LEXER_IF_ELIF         = re.compile(r"^elif\s+(.*)\s*(==|!=)\s*(.*)\s*")
@@ -204,6 +206,18 @@ class Lexer(object):
                if s is None:
                        return ""
 
+               # First run all embedded commands.
+               while s:
+                       m = re.search(LEXER_SHELL, s)
+                       if not m:
+                               break
+
+                       command = m.group(1)
+                       result = self.exec_command(command)
+
+                       s = s.replace("%%(%s)" % command, result or "")
+
+               # Then expand the variables.
                while s:
                        m = re.search(LEXER_VARIABLE, s)
                        if not m:
@@ -214,6 +228,27 @@ class Lexer(object):
 
                return s
 
+       def exec_command(self, command):
+               # Expand all variables in the command.
+               command = self.expand_string(command)
+
+               # If the command is empty, we don't do anything.
+               if not command:
+                       return
+
+               # Do we need to chroot and change personality?
+               try:
+                       output = pakfire.chroot.do(command, shell=True, returnOutput=1, logger=log)
+
+               except Error:
+                       return
+
+               # Strip newline.
+               if output:
+                       output = output.rstrip("\n")
+
+               return output
+
        def get_var(self, key, default=None, raw=False):
                definitions = {}
                definitions.update(self.root.definitions)