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Diffstat (limited to 'winsup/mingw/samples/fixargv/readme.txt')
| -rw-r--r-- | winsup/mingw/samples/fixargv/readme.txt | 85 |
1 files changed, 0 insertions, 85 deletions
diff --git a/winsup/mingw/samples/fixargv/readme.txt b/winsup/mingw/samples/fixargv/readme.txt deleted file mode 100644 index 555ef9bde..000000000 --- a/winsup/mingw/samples/fixargv/readme.txt +++ /dev/null @@ -1,85 +0,0 @@ - -This code is a utility function I was considering adding to Mingw32. The -Microsoft versions of argc, argv construction use quotes and backslashes -to allow the user to pass arguments containing spaces (or quotes) to -programs they invoke. The rules are - - - Arguments containing spaces must be enclosed in quotes. - - A quote can be passed by preceeding it with a backslash. - - Backslashes immediately preceeding a quote must be doubled to avoid - escaping the quote. - -Thus an argument like: - - -D="Foo Bar\\" - -needs to be mangled as: - - "-D\"Foo Bar\\\\\"" - -in order to get to the program as what was intended above. - -The fix_argv set of functions is meant to be used with spawnv and the -like to allow a program to set up an argv array for the spawned program -and have that array duplicated *exactly* in the spawned program, no -matter what it contains (it also quotes 'globbing' characters like * -and ?, so it does not matter if the destination has globbing turned on -or not; it might be a reasonable extension to allow a flag to allow -globbing characters to pass through unmolested, but they would still -be quoted if the string contained whitespace). - -The reason for writing this came up because of problems with arguments -like -DBLAH="Foo Bar" to GCC (define BLAH as a preprocessor constant -being the string "Foo Bar", including the quotes). Because GCC simply -passes the argument directly to CPP (the preprocessor) it had to be -escaped *twice*: - - "-DBLAH=\"\\\"Foo Bar\\\"\"" - -This would reach GCC as - - -DBLAH="\"Foo Bar\"" - -And that would reach CPP as the desired - - -DBLAH="Foo Bar" - -One level of quoting and escaping is to be expected (although MS's -standard is, arguably, not very good), but forcing the user to know -how many different programs the argument is going to pass through, -and perform double quoting and escaping, seems unreasonable. If -GCC and friends all used fix_argv (they use their own version of -it now) then the original argument could be - - "-DBLAH=\"Foo Bar\"" - -And that would work fine, no matter how many different tools it -passed through. - -The only basic limitation with this code is that it assumes that all -the spawned programs use Microsoft-type escaping when interpreting -their command line. Most programs on Win32 machines do (anything -compiled with Mingw32 will). - -For now, this code has been relegated to 'sample' status. If you want -to use it, feel free (it is public domain after all). - -Colin. - -P.S. Just out of interest you might try writing your own little program - to look at the interaction of wildcards and quotes. Use the glob.exe - program in ../globbing and see what it does with - - glob "foo*.txt" - - even if there are files foo.txt and foobar.txt in the same directory. - - Note that - - del "My *.txt" - - works (i.e. it deletes all files starting with My<space>). This could - not be done unless del does globbing *after* processing escapes and - quotes, which is not the way it seems to work normally (again see - the glob example). - |