#!/usr/bin/env python
# tconfpy.py
# Copyright (c) 2003-2004 TundraWare Inc. All Rights Reserved.
# For Updates See: http://www.tundraware.com/Software/tconfpy
# Program Information
PROGNAME = "tconfpy"
RCSID = "$Id: tconfpy.py,v 1.162 2004/04/07 00:10:37 tundra Exp $"
VERSION = RCSID.split()[2]
# Copyright Information
CPRT = chr(169)
DATE = "2003-2004"
OWNER = "TundraWare Inc."
RIGHTS = "All Rights Reserved"
COPYRIGHT = "Copyright %s %s %s, %s." % (CPRT, DATE, OWNER, RIGHTS)
PROGINFO = PROGNAME + " " + VERSION
BANNER = "%s\n%s\n%s\n" % (PROGINFO, COPYRIGHT, RCSID)
#----------------------------------------------------------#
# Variables User Might Change #
#----------------------------------------------------------#
#------------------- Nothing Below Here Should Need Changing -----------------#
#----------------------------------------------------------#
# Imports #
#----------------------------------------------------------#
import os
import platform
import re
from sys import platform as sysplat
#----------------------------------------------------------#
# Aliases & Redefinitions #
#----------------------------------------------------------#
#----------------------------------------------------------#
# Constants & Literals #
#----------------------------------------------------------#
###########
# Constants
###########
# Formatting Constants
MSGPROMPT = "%s>"
FILENUM = "[File: %s Line: %s] " # Display filename and linenum
ATEOF = "EOF" # Use as line number when at EOF
PTR = " ---> " # Textual pointer for debug output
# Special And Reserved Symbols
HASH = r'#'
COMMENT = HASH # Comment introducer character
DELIML = r'[' # Left delimiter for vbl reference
DELIMR = r']' # Right delimiter for vbl reference
DOLLAR = r'$'
ENVIRO = DOLLAR # Used to note environment variable
EQUAL = r'=' # Used in vbl definition
EQUIV = r"==" # Used in conditional tests
NAMESPACE = "NAMESPACE" # Key used to get current namespace
NSSEP = '.' # Namespace separator character
NOTEQUIV = r"!=" # Used in conditional tests
# Pre-Defined System Symbols
PREDEFINTRO = '.'
Predefined = {PREDEFINTRO + "PLATFORM" : sysplat,
PREDEFINTRO + "OSDETAILS" : platform.platform(),
PREDEFINTRO + "OSNAME" : platform.system(),
PREDEFINTRO + "OSRELEASE" : platform.release(),
PREDEFINTRO + "PYTHONVERSION" : platform.python_version(),
PREDEFINTRO + "MACHINENAME" : platform.node()
}
# Control and conditional symbols
CONDINTRO = '.' # Conditional introducer token
INCLUDE = CONDINTRO + "include"
IF = CONDINTRO + "if"
IFALL = IF + "all"
IFANY = IF + "any"
IFNONE = IF + "none"
ELSE = CONDINTRO + "else"
ENDIF = CONDINTRO + "endif"
LITERAL = CONDINTRO + "literal"
ENDLITERAL = CONDINTRO + "endliteral"
Reserved = ["HASH", "DELIML", "DELIMR", "DOLLAR", "EQUAL", "EQUIV", "NOTEQUIV", "NSSEP",
"INCLUDE", "IF", "IFALL", "IFANY", "IFNONE", "ELSE", "ENDIF", "LITERAL", "ENDLITERAL"]
# Regular Expressions
reVARWHITE = r".*\s+.*"
reVARILLEGAL = r"\%s(%s)%s" % (DELIML, reVARWHITE, DELIMR) # Variable reference with spaces in it
reVARREF = r"\%s.+?\%s" % (DELIML, DELIMR) # Variable reference
VarWhite = re.compile(reVARWHITE)
VarIllegal = re.compile(reVARILLEGAL)
VarRef = re.compile(reVARREF)
###########
# Literals
###########
# String Representations Of Booleans
Booleans = {"1" : True, "0" : False,
"True" : True, "False" : False,
"Yes" : True, "No" : False,
"On" : True, "Off" : False
}
sFALSE = "False"
sTRUE = "True"
#----------------------------------------------------------#
# Global Variables & Data Structures #
#----------------------------------------------------------#
ALLOWNEW = True # Allow new variable creation in cfg file
DEBUG = False # Control Debug output
LITERALVARS = False
INLITERAL = False # Indicates we are currently in a literal block
DebugMsg = [] # Place to store and return debug info
ErrMsgs = [] # Place to store and return errors
WarnMsgs = [] # Place to store and return warnings
LiteralLines = [] # Place to store and return unprocessed lines
CondStack = [["", True,]] # Conditional stack
TotalLines = 0 # Total number of lines parsed
#####
# Dummy Object Used To Return Parsing Results
#####
# This is done so the caller only needs to know the name of
# each result set, not its position in the list of returned items
class RetObj(object):
def __init__(self):
self.SymTable = {}
self.Errors = []
self.Warnings = []
self.Debug = []
self.Literals = []
# End of 'RetObj'
##########
# Symbol Table
##########
# Symbol Table is a dictionary in the form:
#
# {varname : descriptor}
#
# where the descriptor is an object with the following attributes
#
# Value, Writeable, Type, Default, LegalVals = [list of legal vals], Min, Max]
#
# Legal Variable Types
TYPE_BOOL = type(True)
TYPE_COMPLEX = type(1-1j)
TYPE_FLOAT = type(3.14)
TYPE_INT = type(1)
TYPE_STRING = type('s')
# Object to hold full description and options for a given variable
class VarDescriptor(object):
# Default variable type is a writeable string with no constraints
def __init__(self):
self.Value = ""
self.Writeable = True
self.Type = TYPE_STRING
self.Default = ""
self.LegalVals = []
self.Min = None
self.Max = None
# End of class 'VarDescriptor'
# Initialize the table using the builtin symbols
SymTable = {}
for sym in Reserved:
descript = VarDescriptor()
descript.Value = eval(sym)
descript.Writeable = False
SymTable[sym] = descript
# Add the predefined symbols
for var in Predefined.keys():
d = VarDescriptor()
d.Value = Predefined[var]
d.Writeable = False
SymTable[var] = d
##########
# Error, Warning, And Debug Message Strings Stored In A Global Dictionary
##########
Messages = {}
#----------------------------------------------------------#
# Prompts, & Application Strings #
#----------------------------------------------------------#
##########
# Debug Literals And Messages
##########
# Literals
dDEBUG = "DEBUG"
dLINEIGNORE = "Line Ignored"
dBLANKLINE = "Parsed To Blank Line. %s" % dLINEIGNORE
dNOTINCLUDE = "Current Conditional Block False. %s" % dLINEIGNORE
# Messages
Messages["dLINEIGNORE"] = FILENUM + " '%s' " + PTR + "%s\n"
Messages["dNUMLINES"] = "Processing File '%s' Resulted In %d Total Lines Parsed"
Messages["dPARSEDLINE"] = FILENUM + " '%s'" + PTR + "'%s'\n"
###########
# Error Literals And Messages
###########
# Literals
eERROR = "ERROR"
eBADDEFAULT = "Type Of Default Value Does Not Agree With Type Declared"
eBADLEGALVAL = "Type Of One Or More LegalVals Does Not Agree With Type Declared"
eBADMINMAX = "Type Of Min Or Max Value Not Appropriate For"
eIFBAD = "'%s' Or '%s' Missing" % (EQUIV, NOTEQUIV)
eNOTDESCRIPT = "Invalid Descriptor Type"
eNOVARREF = "Must Have At Least One Variable Reference"
eSTARTUP = "<Program Starting>"
# Messages
Messages["eBADCOND"] = FILENUM + "Bad '%s' Directive. %s"
Messages["eBADREGEX"] = FILENUM + "Bad Regular Expression, '%s', In Legal Values List For Variable '%s'"
Messages["eBADSYNTAX"] = FILENUM + "Syntax Error. Statement Not In Known Form"
Messages["eCONFOPEN"] = FILENUM + "Cannot Open The File '%s'"
Messages["eDESCRIPTBAD"] = "API Error: %s For Variable '%s'"
Messages["eELSENOIF"] = FILENUM + "'%s' Without Preceding '%s' Form" % (ELSE, IF)
Messages["eENDIFEXTRA"] = FILENUM + "'" + ENDIF + "' Without Matching Condition"
Messages["eENDIFMISS"] = FILENUM + "Missing %d" + " '%s' " % ENDIF + " Statement(s)"
Messages["eEQUIVEXTRA"] = FILENUM + "Only a single '%s' Or '%s' Operator Permitted" % (EQUIV, NOTEQUIV)
Messages["eIFEXTRATXT"] = FILENUM + "Extra Text On Line. '%s' Only Accepts Variable References As Arguments"
Messages["eNOTLEGALVAL"] = FILENUM + "'%s' Not Found In List Of Legal Values For Variable '%s'"
Messages["eSTRINGLONG"] = FILENUM + "Right-Hand-Side Too Long. '%s' Must Be No More Than %s Characters Long"
Messages["eSTRINGSHORT"] = FILENUM + "Right-Hand-Side Too Short. '%s' Must Be At Least %s Characters Long"
Messages["eTYPEBAD"] = FILENUM + "Type Mismatch. '%s' Must Be Assigned Values Of Type %s Only"
Messages["eVALLARGE"] = FILENUM + "%s Is Larger Than The Maximum Allowed, %s, For Variable '%s'"
Messages["eVALSMALL"] = FILENUM + "%s Is Smaller Than The Minimum Allowed, %s, For Variable '%s'"
Messages["eVARRESERVED"] = FILENUM + "Variable Name Cannot Begin With The '%s' Symbol"
Messages["eVARNAMESPC"] = FILENUM + "Variable Names May Not Contain Whitespace"
Messages["eVARNEW"] = FILENUM + "New Variable Creation Not Permitted"
Messages["eVARNONAME"] = FILENUM + "Variable Name Evaluates To Null String. Not Permitted"
Messages["eVARREADONLY"] = FILENUM + "Variable '%s' Is Read-Only. Cannot Change Its Value"
Messages["eVARUNDEF"] = FILENUM + "Attempt To Reference Undefined Variable '%s'"
###########
# Warning Literals And Messages
###########
# Literals
wWARNING = "WARNING"
# Messages
Messages["wENDLITEXTRA"] = FILENUM + "'%s' Statement Without Preceding '%s'. Statement Ignored" % (ENDLITERAL, LITERAL)
Messages["wENDLITMISS"] = FILENUM + "Missing '%s' Statement. All lines treated literally to end-of-file" % ENDLITERAL
Messages["wLITEXTRA"] = FILENUM + "Already In A Literal Block. '%s' Statement Ignored" % LITERAL
# Determine Length Of Longest Message Type
# Needed for formatting later
MAXMSG = 0
for msg in Messages:
l = len(msg)
if l > MAXMSG:
MAXMSG = l
#--------------------------- Code Begins Here ---------------------------------#
#----------------------------------------------------------#
# Utility Function Definitions #
#----------------------------------------------------------#
##########
# Create A Debug Message
##########
def DebugMsg(dmsg, args):
global DebugMsgs
DebugMsgs.append(mkmsg(Messages[dmsg] % args, dmsg))
# End of 'DebugMsg()'
##########
# Create An Error Message
##########
def ErrorMsg(error, args):
global ErrMsgs
ErrMsgs.append(mkmsg(Messages[error] % args + "!", error))
# End of 'ErrorMsg()'
##########
# Create A Warning Message
##########
def WarningMsg(warning, args):
global WarnMsgs
WarnMsgs.append(mkmsg(Messages[warning] % args + "!", warning))
# End of 'WarningMsg()'
##########
# Construct A Standard Application Message String
##########
def mkmsg(msg, msgtype):
pad = " " * (MAXMSG - len(msgtype) + 2)
return "%s %s%s%s" % (PROGINFO, MSGPROMPT % msgtype, pad, msg)
# End of 'mkmsg()'
#----------------------------------------------------------#
# Public API To Module #
#----------------------------------------------------------#
def ParseConfig(cfgfile, InitialSymTbl={}, AllowNewVars=True, Debug=False, LiteralVars=False):
global DebugMsgs, ErrMsgs, WarnMsgs, LiteralLines
global CondStack, ALLOWNEW, DEBUG, SymTable, TotalLines, LITERALVARS, INLITERAL
# Initialize the globals
ALLOWNEW = AllowNewVars
DEBUG = Debug
LITERALVARS = LiteralVars
DebugMsgs = []
ErrMsgs = []
WarnMsgs = []
LiteralLines = []
retobj = RetObj()
CondStack = [["", True],] # Always has one entry as a sentinel
TotalLines = 0
# Add any passed symbols to the SymbolTable
deserror = False
for sym in InitialSymTbl:
des = InitialSymTbl[sym]
# Make sure a valid descriptor was passed for each variable
desok = True
# Make sure we got a Var Descriptor Object
if not isinstance(des, VarDescriptor):
desok = False
ErrorMsg("eDESCRIPTBAD", (eNOTDESCRIPT, sym))
des = VarDescriptor() # Make a fake one so the following tests don't blow up
# Check various entries for type agreement
dt = des.Type
if des.Default and type(des.Default) != dt:
desok = False
ErrorMsg("eDESCRIPTBAD", (eBADDEFAULT, sym))
for lv in des.LegalVals:
if type(lv) != dt:
desok = False
ErrorMsg("eDESCRIPTBAD", (eBADLEGALVAL, sym))
for mm in (des.Min, des.Max):
# Floats can accept Float or Int boundaries
# Ints, & Strings can accept Int boundaries
# Boundaries not relevant for Bool and Complex
# Anything else is an error
if mm and dt == TYPE_FLOAT and type(mm) != TYPE_FLOAT and type(mm) != TYPE_INT:
desok = False
ErrorMsg("eDESCRIPTBAD", (eBADMINMAX, sym))
if mm and dt in (TYPE_INT, TYPE_STRING) and type(mm) != TYPE_INT:
desok = False
ErrorMsg("eDESCRIPTBAD", (eBADMINMAX, sym))
# Only load the symbol table with valid entries
if desok:
SymTable[sym] = des
# Indicate that a problem was encountered
else:
deserror = True
# If any of the passed symbols had bogus descriptor contents, we're done
if deserror:
retobj.SymTable = SymTable
retobj.Errors = ErrMsgs
retobj.Warnings = WarnMsgs
retobj.Debug = DebugMsgs
retobj.Literals = LiteralLines
return retobj
# Symbol Table passed to API was OK, sokeep going
# Make sure the symbol table has a valid namespace
if NAMESPACE not in SymTable:
SymTable[NAMESPACE] = VarDescriptor()
SymTable[NAMESPACE].Value = ""
SymTable[NAMESPACE].LegalVals.append("")
# Parse the file
ParseFile(cfgfile, eSTARTUP, 0)
# Make sure we had all condition blocks balanced with matching '.endif'
finalcond = len(CondStack)
if finalcond != 1:
ErrorMsg("eENDIFMISS", (cfgfile, ATEOF, finalcond-1))
# Make sure we ended any literal processing properly
if INLITERAL:
WarningMsg("wENDLITMISS", (cfgfile, ATEOF))
# Return the parsing results
if DEBUG:
DebugMsg("dNUMLINES", (cfgfile, TotalLines))
retobj.SymTable = SymTable
retobj.Errors = ErrMsgs
retobj.Warnings = WarnMsgs
retobj.Debug = DebugMsgs
retobj.Literals = LiteralLines
return retobj
# End of 'ParseConfig()'
#----------------------------------------------------------#
# Parser Support Functions #
#----------------------------------------------------------#
##########
# Condition A Line - Remove Comments & Leading/Trailing Whitespace
##########
def ConditionLine(line):
return line.split(COMMENT)[0].strip()
# End of 'ConditionLine()'
##########
# Dereference Variables
##########
def DerefVar(line, cfgfile, linenum, reporterr=True):
# Find all symbols refrences and replace w/sym table entry if present
ref_ok = True
for var in VarRef.findall(line):
sym = var[1:-1] # Strip delimiters
# By default, all variable names assumed to be relative to
# current namespace context unless escaped with NSSEP
# Look for an escape
if sym and sym[0] == NSSEP:
sym = sym[1:]
# Prepend the current namespace for all but the top level
elif SymTable[NAMESPACE].Value:
sym = "%s%s%s" % (SymTable[NAMESPACE].Value, NSSEP, sym)
# Handle environment variables
if sym and sym[0] == ENVIRO and sym[1:] in os.environ:
line = line.replace(var, os.getenv(sym[1:]))
# Handle variables in symbol table
elif sym in SymTable:
line = line.replace(var, str(SymTable[sym].Value))
# Reference to undefined variable
else:
# There are times a reference to an undefined variable
# should not produce and error message. For example,
# during existential conditional processing, we just
# want to check whether variables are defined or not.
# Attempts to reference undefined variables are legitimate
# in this case and ought not to generate an error message.
if reporterr:
ErrorMsg("eVARUNDEF", (cfgfile, linenum, sym))
ref_ok = False
return line, ref_ok
# End of 'DerefVar()'
##########
# Parse A File
##########
def ParseFile(cfgfile, current_cfg, current_linenum):
global IgnoreCase, MsgList, SymTable, TotalLines
linenum=0
try:
cf = open(cfgfile)
# Process and massage the configuration file
for line in cf.read().splitlines():
linenum += 1
TotalLines += 1
# Parse this line
ParseLine(line, cfgfile, linenum)
# Close the config file
cf.close()
# File open failed for some reason
except IOError:
ErrorMsg("eCONFOPEN", (current_cfg, current_linenum, cfgfile)) # Record the error
# End of 'ParseFile()'
##########
# Parse A Line
##########
def ParseLine(line, cfgfile, linenum):
global CondStack, MsgList, SymTable, INLITERAL
orig = line # May need copy of original for debug output
##########
# Beginning Of Line Parser
##########
#####
# LITERAL and ENDLITERAL Processing
# These get highest precedence because they block everything else.
# However, they are ignored within False conditional blocks.
#####
if line.strip() in (LITERAL, ENDLITERAL):
if not CondStack[-1][1]:
if DEBUG:
DebugMsg("dLINEIGNORE", (cfgfile, linenum, orig, dNOTINCLUDE))
return
if line.strip() == LITERAL:
if INLITERAL:
WarningMsg("wLITEXTRA", (cfgfile, linenum))
else:
INLITERAL = True
# Process ENDLITERAL statements
else:
if not INLITERAL:
WarningMsg("wENDLITEXTRA", (cfgfile, linenum))
else:
INLITERAL = False
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
# We pass lines as-is, with optional variable replacement, in literal blocks
if INLITERAL:
if LITERALVARS:
line, ref_ok = DerefVar(line, cfgfile, linenum)
LiteralLines.append(line)
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
line = ConditionLine(line) # Strip out comments and leading/trailing whitespace
condstate = True # Results of conditional tests kept here
# Only attempt on non-blank lines for everything else
# Line was blank
if not line:
# Note blank lines for debug purposes
if DEBUG:
DebugMsg("dLINEIGNORE", (cfgfile, linenum, orig, dBLANKLINE))
return
# Get first token on the line
FIRSTTOK = line.split()[0]
#####
# ELSE Processing
#####
if line == ELSE:
# Get the enclosing block type and state
btyp, bst = CondStack.pop()
# ELSE is only permitted after an immediately preceding IF form
if btyp != IF:
ErrorMsg("eELSENOIF", (cfgfile, linenum))
CondStack.append(["", False]) # Error makes all that follows False
# We *are* in an IF block an ELSE is appropriate.
# To determine whether the ELSE should be taken or not we have
# to look at the state of that IF block AND the state of
# the block that contains the IF. This is because the IF
# block state is the AND of the state of its parent block
# and its own logical state - i.e. A block can be made
# logically False by its containing block even if the condition
# tested is True.
else:
# If the containing block is True, the contained IF state is legitimate.
# The ELSE inverts the IF state in that case.
if CondStack[-1][1]:
CondStack.append([ELSE, not bst])
# The containing block is false, so everything within it is also false
else:
CondStack.append([ELSE, False])
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
#####
# ENDIF Processing
#####
if line == ENDIF:
# Remove one level of conditional nesting
CondStack.pop()
# Error, if there are more .endifs than conditionals
if not CondStack:
ErrorMsg("eENDIFEXTRA", (cfgfile, linenum))
CondStack.append(["", False]) # Restore sentinel & inhibit further parsing
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
#####
# Namespace Processing
#####
if line == DELIML+DELIMR or (len(VarRef.findall(line)) == 1 and \
line[0] == DELIML and line[-1] == DELIMR and\
line.count(DELIML) == line.count(DELIMR) == 1):
if not CondStack[-1][1]:
if DEBUG:
DebugMsg("dLINEIGNORE", (cfgfile, linenum, orig, dNOTINCLUDE))
return
# Set the new namespace
ns = line[1:-1]
SymTable[NAMESPACE].Value = ns
# Save newly seen namespaces in list of legal vals
if ns not in SymTable[NAMESPACE].LegalVals:
SymTable[NAMESPACE].LegalVals.append(ns)
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
#####
# INCLUDE Processing
#####
elif FIRSTTOK == INCLUDE:
if not CondStack[-1][1]:
if DEBUG:
DebugMsg("dLINEIGNORE", (cfgfile, linenum, orig, dNOTINCLUDE))
return
line, ref_ok = DerefVar(line.split(INCLUDE)[1].strip(), cfgfile, linenum)
# Only attempt the include if all the variable dereferencing was successful
if ref_ok:
ParseFile(line, cfgfile, linenum)
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
#####
# Conditional Processing
#
# Must be one of the following forms -
#
# IFALL [var] ...
# IFANY [var] ...
# IFNONE [var] ...
# IF string == string
# IF string != string
#
# where string can be any concatentation of text and variable references
#
#####
# Is it any of the IF forms?
elif FIRSTTOK in (IF, IFALL, IFANY, IFNONE):
#####
# Existential Conditionals
#####
if FIRSTTOK in (IFALL, IFANY, IFNONE):
if FIRSTTOK == IFALL:
line = line.split(IFALL)[1].strip()
elif FIRSTTOK == IFANY:
line = line.split(IFANY)[1].strip()
else:
line = line.split(IFNONE)[1].strip()
# There must be at least one var reference in the condition
vars = VarRef.findall(line)
# Only variable references are significant - warn on other text.
# Strip out variable references and see if anything
# other than whitespace is left.
plain = line
if vars:
for v in vars:
plain=plain.replace(v, "")
# Only arguments that are allowed are variable references
if len(plain.strip()):
ErrorMsg("eIFEXTRATXT", (cfgfile, linenum, FIRSTTOK))
condstate = False
if vars:
# Only do this if the syntax check above was OK
if condstate:
# Go see how many references actually resolve
resolved = 0
for v in vars:
v, ref_ok = DerefVar(v, cfgfile, linenum, reporterr=False)
if ref_ok:
resolved += 1
# And set the conditional state accordingly
if FIRSTTOK == IFALL and len(vars) != resolved:
condstate = False
if FIRSTTOK == IFANY and not resolved:
condstate = False
if FIRSTTOK == IFNONE and resolved:
condstate = False
# Bogus conditional syntax - no variable refs found
else:
ErrorMsg("eBADCOND", (cfgfile, linenum, FIRSTTOK, eNOVARREF))
# Force parse state to False on an error
condstate = False
#####
# (In)Equality Conditionals - IF string EQUIV/NOTEQUIV string forms
#####
else:
line = line.split(IF)[1].strip()
if EQUIV in line or NOTEQUIV in line:
# Only one operator permitted
if (line.count(EQUIV) + line.count(NOTEQUIV)) > 1:
ErrorMsg("eEQUIVEXTRA", (cfgfile, linenum))
condstate = False
else:
# Dereference all variables
line, ref_ok = DerefVar(line, cfgfile, linenum)
# Reference to undefined variables forces False
if not ref_ok:
condstate = False
# So does a failure of the equality test itself
else:
invert = False
operator = EQUIV
condstate = True
if operator not in line: # Must be NOTEQUIV
invert = True
operator = NOTEQUIV
line = line.split(operator)
if line[0].strip() != line[1].strip():
condstate = False
if invert:
condstate = not condstate
# Conditional Syntax Error
else:
ErrorMsg("eBADCOND", (cfgfile, linenum, FIRSTTOK, eIFBAD))
# Force parse state to False on an error
condstate = False
# Set parser state based on a successful conditional test
# But it has to be ANDed with the state of the enclosing block
enclosing = CondStack[-1][1]
CondStack.append([IF, condstate and enclosing])
# Now reflect this in the parsed line
line = sTRUE
if not condstate:
line = sFALSE
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
#####
# Handle Variable Declaration/Assignment
#####
# If we got here it means that none of the conditional forms
# were found, so the only thing left might be a variable
# definition/assignment.
elif EQUAL in line:
if not CondStack[-1][1]:
if DEBUG:
DebugMsg("dLINEIGNORE", (cfgfile, linenum, orig, dNOTINCLUDE))
return
# Catch attempts to use whitespace within variable names or references
if VarIllegal.findall(line) or VarWhite.findall(line.split(EQUAL)[0].strip()):
ErrorMsg("eVARNAMESPC", (cfgfile, linenum))
return
# Catch attempts to dereference without name
if line.count(DELIML + DELIMR):
ErrorMsg("eVARNONAME", (cfgfile, linenum))
return
# Do any necessary variable dereferencing
line, ref_ok = DerefVar(line, cfgfile, linenum)
# Only do this if all var references were valid
if ref_ok:
# Get left and right sides of the assignment
e = line.index(EQUAL)
l = line[:e].strip()
r = line[e+1:].strip()
# Suppress attempts to set null-named variables
if not l:
ErrorMsg("eVARNONAME", (cfgfile, linenum))
# Suppress attempts to set variables named starting
# with certain reserved symbols because dereferencing
# such variable names is impossible
elif l[0] in (COMMENT, ENVIRO):
ErrorMsg("eVARRESERVED", (cfgfile, linenum, l[0]))
# Suppress any attempt to change a RO variable
elif l in SymTable and not SymTable[l].Writeable:
ErrorMsg("eVARREADONLY", (cfgfile, linenum, l))
# Load variable into the symbol table
else:
# Munge the variable name to incorporate
# the current namespace
# The NAMESPACE variable is special - It is presumed to reset
# the top level namespace.
if l in (NAMESPACE, NSSEP+NAMESPACE):
if l == NSSEP + NAMESPACE:
l=NAMESPACE
# Save the new namespace
SymTable[NAMESPACE].Value = r
# Add to unique list of namespaces seen
if r not in SymTable[NAMESPACE].LegalVals:
SymTable[NAMESPACE].LegalVals.append(r)
# Handle absolute variable references
elif l.startswith(NSSEP):
l = l[1:]
# In all other cases prepend current namespace
else:
ns = SymTable[NAMESPACE].Value
# Top level namespace variables don't need separator
if ns:
l = "%s%s%s" % (ns, NSSEP, l)
d = VarDescriptor()
# If this is a newly defined variable, set its
# default to be this first value assigned and
# create the new entry
if l not in SymTable:
# Only do this if new variable creation allowed
if ALLOWNEW:
d.Default = r
d.Value = r
SymTable[l] = d
# New vars not allowed
else:
ErrorMsg("eVARNEW", (cfgfile, linenum))
# Otherwise, update an existing entry.
# For existing entries we have to first
# do the various validation checks specified
# in that variable's descriptor
else:
update = True
des = SymTable[l]
typ = des.Type
lv = des.LegalVals
low = des.Min
up = des.Max
#####
# Type Enforcement
#####
# We try to coerce the new value into
# the specified type. If this works, we
# go on to the rest of the validation tests,
# otherwise mark the attempt as invalid.
try:
# Booleans are a special case - we accept only
# a limited number of strings on the RHS
if typ == TYPE_BOOL:
r = Booleans[r.capitalize()]
# For everything else, try an explicit coercion
else:
r = typ(r)
except:
update = False
ErrorMsg("eTYPEBAD", (cfgfile, linenum, l, str(typ).split()[1][:-1]))
#####
# Legal Values Enforcement
#####
# These tests valid for everything except booleans.
# An empty LegalVals list means this test is skipped.
# For all numeric types, the test is to see if the new
# value is one of the ones enumerated in LegalVals.
#
# For strings, LegalVals is presumed to contain a list
# of regular expressions. The test is to compile each
# regex and see if any match the new value.
if update and lv:
if typ in (TYPE_COMPLEX, TYPE_FLOAT, TYPE_INT):
if r not in lv:
ErrorMsg("eNOTLEGALVAL", (cfgfile, linenum, r, l))
update = False
elif typ == TYPE_STRING:
foundmatch = False
for rex in lv:
try:
rexc=re.compile(rex)
if rexc.match(r):
foundmatch = True
except:
ErrorMsg("eBADREGEX", (cfgfile, linenum, rex, l))
update = False
if not foundmatch:
ErrorMsg("eNOTLEGALVAL", (cfgfile, linenum, r, l))
update = False
#####
# Bounds Checks
#####
# Check bounds for interger and floats
if update and typ in (TYPE_FLOAT, TYPE_INT):
if low != None and r < low:
ErrorMsg("eVALSMALL", (cfgfile, linenum, r, low, l))
update = False
if up != None and r > up:
ErrorMsg("eVALLARGE", (cfgfile, linenum, r, up, l))
update = False
# Check bounds for strings - these are min/max string lengths, if present
if update and typ == TYPE_STRING:
if low != None and len(r) < low:
ErrorMsg("eSTRINGSHORT", (cfgfile, linenum, l, low))
update = False
if up != None and len(r) > up:
ErrorMsg("eSTRINGLONG", (cfgfile, linenum, l, up))
update = False
# Update variable if all tests passed
if update:
SymTable[l].Value = r
if DEBUG:
DebugMsg("dPARSEDLINE", (cfgfile, linenum, orig, line))
return
#####
# Line Format Is Not In One Of The Recognized Forms - Syntax Error
#####
else:
ErrorMsg("eBADSYNTAX", (cfgfile, linenum))
##########
# End Of Line Parser
##########
# End of 'ParseLine'
#----------------------------------------------------------#
# List Of Public Names Available To Program Importing Us #
#----------------------------------------------------------#
__all__ = ["ParseConfig",
"RetObj",
"TYPE_BOOL",
"TYPE_COMPLEX",
"TYPE_FLOAT",
"TYPE_INT",
"TYPE_STRING",
"VarDescriptor"
]
#----------------------------------------------------------#
# Entry Point On Direct Invocation #
#----------------------------------------------------------#
if __name__ == '__main__':
# Print program information
print BANNER
# Print things we know about the environment
pk = Predefined.keys()
pk.sort()
for var in pk:
val = Predefined[var]
print "%s%s%s" % (var, (20-len(var)) * " ", val)
tundra