shell bypass 403
"""
takes templated file .xxx.src and produces .xxx file where .xxx is
.i or .c or .h, using the following template rules
/**begin repeat -- on a line by itself marks the start of a repeated code
segment
/**end repeat**/ -- on a line by itself marks it's end
After the /**begin repeat and before the */, all the named templates are placed
these should all have the same number of replacements
Repeat blocks can be nested, with each nested block labeled with its depth,
i.e.
/**begin repeat1
*....
*/
/**end repeat1**/
When using nested loops, you can optionally exclude particular
combinations of the variables using (inside the comment portion of the inner loop):
:exclude: var1=value1, var2=value2, ...
This will exclude the pattern where var1 is value1 and var2 is value2 when
the result is being generated.
In the main body each replace will use one entry from the list of named replacements
Note that all #..# forms in a block must have the same number of
comma-separated entries.
Example:
An input file containing
/**begin repeat
* #a = 1,2,3#
* #b = 1,2,3#
*/
/**begin repeat1
* #c = ted, jim#
*/
@a@, @b@, @c@
/**end repeat1**/
/**end repeat**/
produces
line 1 "template.c.src"
/*
*********************************************************************
** This file was autogenerated from a template DO NOT EDIT!!**
** Changes should be made to the original source (.src) file **
*********************************************************************
*/
#line 9
1, 1, ted
#line 9
1, 1, jim
#line 9
2, 2, ted
#line 9
2, 2, jim
#line 9
3, 3, ted
#line 9
3, 3, jim
"""
from __future__ import division, absolute_import, print_function
__all__ = ['process_str', 'process_file']
import os
import sys
import re
from numpy.distutils.compat import get_exception
# names for replacement that are already global.
global_names = {}
# header placed at the front of head processed file
header =\
"""
/*
*****************************************************************************
** This file was autogenerated from a template DO NOT EDIT!!!! **
** Changes should be made to the original source (.src) file **
*****************************************************************************
*/
"""
# Parse string for repeat loops
def parse_structure(astr, level):
"""
The returned line number is from the beginning of the string, starting
at zero. Returns an empty list if no loops found.
"""
if level == 0 :
loopbeg = "/**begin repeat"
loopend = "/**end repeat**/"
else :
loopbeg = "/**begin repeat%d" % level
loopend = "/**end repeat%d**/" % level
ind = 0
line = 0
spanlist = []
while True:
start = astr.find(loopbeg, ind)
if start == -1:
break
start2 = astr.find("*/", start)
start2 = astr.find("\n", start2)
fini1 = astr.find(loopend, start2)
fini2 = astr.find("\n", fini1)
line += astr.count("\n", ind, start2+1)
spanlist.append((start, start2+1, fini1, fini2+1, line))
line += astr.count("\n", start2+1, fini2)
ind = fini2
spanlist.sort()
return spanlist
def paren_repl(obj):
torep = obj.group(1)
numrep = obj.group(2)
return ','.join([torep]*int(numrep))
parenrep = re.compile(r"[(]([^)]*)[)]\*(\d+)")
plainrep = re.compile(r"([^*]+)\*(\d+)")
def parse_values(astr):
# replaces all occurrences of '(a,b,c)*4' in astr
# with 'a,b,c,a,b,c,a,b,c,a,b,c'. Empty braces generate
# empty values, i.e., ()*4 yields ',,,'. The result is
# split at ',' and a list of values returned.
astr = parenrep.sub(paren_repl, astr)
# replaces occurrences of xxx*3 with xxx, xxx, xxx
astr = ','.join([plainrep.sub(paren_repl, x.strip())
for x in astr.split(',')])
return astr.split(',')
stripast = re.compile(r"\n\s*\*?")
named_re = re.compile(r"#\s*(\w*)\s*=([^#]*)#")
exclude_vars_re = re.compile(r"(\w*)=(\w*)")
exclude_re = re.compile(":exclude:")
def parse_loop_header(loophead) :
"""Find all named replacements in the header
Returns a list of dictionaries, one for each loop iteration,
where each key is a name to be substituted and the corresponding
value is the replacement string.
Also return a list of exclusions. The exclusions are dictionaries
of key value pairs. There can be more than one exclusion.
[{'var1':'value1', 'var2', 'value2'[,...]}, ...]
"""
# Strip out '\n' and leading '*', if any, in continuation lines.
# This should not effect code previous to this change as
# continuation lines were not allowed.
loophead = stripast.sub("", loophead)
# parse out the names and lists of values
names = []
reps = named_re.findall(loophead)
nsub = None
for rep in reps:
name = rep[0]
vals = parse_values(rep[1])
size = len(vals)
if nsub is None :
nsub = size
elif nsub != size :
msg = "Mismatch in number of values, %d != %d\n%s = %s"
raise ValueError(msg % (nsub, size, name, vals))
names.append((name, vals))
# Find any exclude variables
excludes = []
for obj in exclude_re.finditer(loophead):
span = obj.span()
# find next newline
endline = loophead.find('\n', span[1])
substr = loophead[span[1]:endline]
ex_names = exclude_vars_re.findall(substr)
excludes.append(dict(ex_names))
# generate list of dictionaries, one for each template iteration
dlist = []
if nsub is None :
raise ValueError("No substitution variables found")
for i in range(nsub) :
tmp = {}
for name, vals in names :
tmp[name] = vals[i]
dlist.append(tmp)
return dlist
replace_re = re.compile(r"@([\w]+)@")
def parse_string(astr, env, level, line) :
lineno = "#line %d\n" % line
# local function for string replacement, uses env
def replace(match):
name = match.group(1)
try :
val = env[name]
except KeyError:
msg = 'line %d: no definition of key "%s"'%(line, name)
raise ValueError(msg)
return val
code = [lineno]
struct = parse_structure(astr, level)
if struct :
# recurse over inner loops
oldend = 0
newlevel = level + 1
for sub in struct:
pref = astr[oldend:sub[0]]
head = astr[sub[0]:sub[1]]
text = astr[sub[1]:sub[2]]
oldend = sub[3]
newline = line + sub[4]
code.append(replace_re.sub(replace, pref))
try :
envlist = parse_loop_header(head)
except ValueError:
e = get_exception()
msg = "line %d: %s" % (newline, e)
raise ValueError(msg)
for newenv in envlist :
newenv.update(env)
newcode = parse_string(text, newenv, newlevel, newline)
code.extend(newcode)
suff = astr[oldend:]
code.append(replace_re.sub(replace, suff))
else :
# replace keys
code.append(replace_re.sub(replace, astr))
code.append('\n')
return ''.join(code)
def process_str(astr):
code = [header]
code.extend(parse_string(astr, global_names, 0, 1))
return ''.join(code)
include_src_re = re.compile(r"(\n|\A)#include\s*['\"]"
r"(?P<name>[\w\d./\\]+[.]src)['\"]", re.I)
def resolve_includes(source):
d = os.path.dirname(source)
fid = open(source)
lines = []
for line in fid:
m = include_src_re.match(line)
if m:
fn = m.group('name')
if not os.path.isabs(fn):
fn = os.path.join(d, fn)
if os.path.isfile(fn):
print('Including file', fn)
lines.extend(resolve_includes(fn))
else:
lines.append(line)
else:
lines.append(line)
fid.close()
return lines
def process_file(source):
lines = resolve_includes(source)
sourcefile = os.path.normcase(source).replace("\\", "\\\\")
try:
code = process_str(''.join(lines))
except ValueError:
e = get_exception()
raise ValueError('In "%s" loop at %s' % (sourcefile, e))
return '#line 1 "%s"\n%s' % (sourcefile, code)
def unique_key(adict):
# this obtains a unique key given a dictionary
# currently it works by appending together n of the letters of the
# current keys and increasing n until a unique key is found
# -- not particularly quick
allkeys = list(adict.keys())
done = False
n = 1
while not done:
newkey = "".join([x[:n] for x in allkeys])
if newkey in allkeys:
n += 1
else:
done = True
return newkey
if __name__ == "__main__":
try:
file = sys.argv[1]
except IndexError:
fid = sys.stdin
outfile = sys.stdout
else:
fid = open(file, 'r')
(base, ext) = os.path.splitext(file)
newname = base
outfile = open(newname, 'w')
allstr = fid.read()
try:
writestr = process_str(allstr)
except ValueError:
e = get_exception()
raise ValueError("In %s loop at %s" % (file, e))
outfile.write(writestr)