Among many WinDbg scripting language flaws is a complete lack of advanced text searching/replacing functionality, especially associated with aliases. The library provides simple, "s" sed like command to search and replace regexp patterns in strings and WinDbg aliases. Together with WinDbg functionality of setting aliases to arbitrary WinDbg commands outputs, the library provides an effective tool to write advanced WinDbg scripts without a need to reach for Python substitutions.
Additionally the library supplies simple set of commands to open, read, write and close text/binary files. Of course this ain't shell nor Python but for simple scripts should be sufficient.
NOTE: Since my contact with Windows platform and the WinDbg debugger is currently rather occasional, the project is no more maintained. If someone is interested to continue work on it, feel free to contact me.
scriptext: Various scripting utilities
sxtr [-t num] input/pattern/replacement
Look for a substring of the input string matching the extended POSIX RE pattern.
If the pattern matches, the substring is extracted and modified according to
the replacement string. The input string may contain alphanumeric characters
plus '_' only, or must be enclosed in '' or "". If it's enclosed in [], then
the input string specifies an alias name containing a string to process.
Delimiter character is recognized as the first one after the input string. All
the strings may contain escaped characters.
-t: If specified, provides a pseudo-reg $t number where the matching result
will be set: 0 - not matched, 1 - matched.
fopn [-m mode] [-t num] fname
Open a file with a name fname.
-m: Open mode (C standard). "r+" by default.
-t: Pseudo-reg $t number where a handle of the opened file will be written. In
case of opening error zero will be written there. If not specified $t0 is
taken.
fwrt hndl input
Write the input string to the file with the handle hndl. If the input string
is enclosed in [] then it specifies an alias name containing a string to write.
The input string may contain escaped characters.
frdl hndl
Read line from a file with the handle hndl. The file shall be opened for read
in the text mode.
fcls hndl
Close a file with a handle hndl.
help
Display this help.
Prerequisites:
- MS SDK with
cl,linkandnmake; no need for MS Visual Studio, - Debugging Tools for Windows with its SDK,
Compilation:
Set required building environment depending on your target platform (x86/x64/ia64,
debug/release etc.) by calling MS SDK's SetEnv.Cmd script with proper arguments
and make the library:
nmake
The result is scriptext.dll library located in the sources directory. Install
it by:
nmake install
I. Loading
0:000> .load scriptext
II. Help info
0:000> !scriptext.help
III. Text searching and replacement
Create test_alias alias, look for test string in it and replace by TEST.
$t0 pseudo register is set to 1 (the searched string is found in the alias).
0:000> aS test_alias "Let's try test"
0:000> al
Alias Value
------- -------
test_alias Let's try test
0:000> !sxtr -t0 [test_alias]/(.*)test(.*)/\1TEST\2
Let's try TEST
0:000> r @$t0
$t0=0000000000000001
Look for test and TEST substrings in test_alias and set $t0 pseudo
register as a result of searching. Searching is performed on the alias
substitution.
0:000> !sxtr "-t0 \"${test_alias}\"/test"
0:000> r @$t0
$t0=0000000000000001
0:000> !sxtr "-t0 \"${test_alias}\"/TEST"
0:000> r @$t0
$t0=0000000000000000
IV. Simple grep
Create the following script with filename simple_grep:
!fopn -m "r" ${$arg1}
.if (@$t0!=0) {
aS /c ${/v:ln} !frdl @$t0
.while (1) {
!sxtr -t1 [ln]/.+
.if (@$t1!=0) {
!sxtr -t1 [ln]/${$arg2}
.if (@$t1!=0) {
.echo ${ln}
}
} .else {
.break
}
aS /c ${/v:ln} !frdl @$t0
}
!fcls @$t0
ad /q ${/v:ln}
}
and execute it with 2 arguments: input file and searched RE pattern:
0:000> $$>a< simple_grep file pattern
GNU GENERAL PUBLIC LICENSE v2. See LICENSE file for details.