busybox-w32/editors, branch su_cmd

win32: add support for virtual terminal input

2023-03-05T12:43:46+00:00

Alter certain applets to support virtual terminal input, if enabled. In many places this is achieved by building previously excluded upstream terminal-handling code. The busybox-w32 implementation of termios(3) functions does nothing if virtual terminal input is disabled, so it can be invoked regardless. Some applet-specific terminal-handling code is also required. This affects less, more, vi and command line editing in the shell. (The `more` applet isn't enabled in the default configuration.) This series of patches adds about 1.7KB to the binaries.

Merge branch 'busybox' into merge

2023-02-13T10:01:35+00:00

vi: introduce 'binary' option and '-b' flag

2023-02-06T11:15:37+00:00

vim has the 'binary' option and corresponding '-b' command line flag. These allow files to be opened in binary mode, ignoring the 'fileformats' setting and treating all files as of type 'unix'. Add these to busybox-w32 vi so it's possible to edit files which have a mixture of different line endings. Costs 80-112 bytes. (GitHub issue #285)

vi: allow change of 'fileformat' option

2023-02-06T10:46:54+00:00

For some reason the 'fileformat' option was made read-only when it was introduced in commit 420afde92e (vi: add fileformats option). I think I'd read some vim documentation that made it seem more complicated than it really is. Costs 48 bytes.

awk: CRLF handling

2023-01-30T10:33:59+00:00

Previous efforts at handling DOS-style line endings in awk have included commits ee7e00dc5 and 1a3717342. The use of remove_cr() is unwise: - It's overzealous, removing all CRs, not just those in CRLF pairs. - Even if that were fixed awk reads input in chunks. There's a remote chance a CRLF might appear at a chunk boundary and be missed. remove_cr() will be fixed separately. In awk treat all data input as being in text mode. Skipping CRs in skip_spaces() is also flawed. Instead read scripts in text mode. Add a couple of test cases. One of these (awk backslash+CRLF eaten with no trace) fails without this patch.

diff: improve --binary implementation

2023-01-29T11:28:19+00:00

Commit 82f0d19b1 (diff: implement --binary flag) was both over- complicated and incorrect. If stdin was seekable it was left in binary mode even if the --binary flag wasn't supplied. Always open files in binary mode. Only switch to text mode at the last moment, if necessary. Saves 48 bytes.

diff: implement --binary flag

2023-01-27T13:27:29+00:00

On Windows GNU diff uses text mode for input and output. It also has the '--binary' flag to use binary mode instead. On Unix binary mode is the default and the flag does nothing. Alter diff to use text mode by default for input (though not output, let's not go overboard). Add the '--binary' flag to override this. Costs 96-160 bytes.

awk: further improvements to randomness

2023-01-11T08:13:53+00:00

POSIX requires that the awk srand() function uses the time of day to seed the PRNG. The obvious implementation used in BusyBox does exactly that, passing time(NULL) to srand(3). When processes are started within a few seconds of one another their seeds are very similar. Given the realtively poor quality of rand(3) in some C runtimes this results in random number sequences that are somewhat correlated. Improve matters by using an integer hash on the seed, as recommended here: https://nullprogram.com/blog/2019/04/30/#the-wrong-places Costs 48 bytes. (GitHub issue #279)

awk: make random values more random

2023-01-06T15:51:30+00:00

When srand(3) is called to seed the random number generator with the current time the first value returned by rand(3) changes slowly with time. This is a property of the implementation in the C runtime. Change the order in which values from rand(3) are consumed to generate the value returned by the awk rand() function. This puts the value returned by the first call to rand(3) in the least significant bits, not the most significant. (GitHub issue #279)

ed: don't use memcpy with overlapping memory regions

2023-01-05T15:21:48+00:00

The memcpy invocations in the subCommand function, modified by this commit, previously used memcpy with overlapping memory regions. This is undefined behavior. On Alpine Linux, it causes BusyBox ed to crash since we compile BusyBox with -D_FORTIFY_SOURCE=2 and our fortify-headers implementation catches this source of undefined behavior [0]. The issue can only be triggered if the replacement string is the same size or shorter than the old string. Looking at the code, it seems to me that a memmove(3) is what was actually intended here, this commit modifies the code accordingly. [0]: https://gitlab.alpinelinux.org/alpine/aports/-/issues/13504 Signed-off-by: Sören Tempel Signed-off-by: Denys Vlasenko