src/usr.bin/diff/diff.1, branch releng/12.2

MFC r357875: diff: fix segfault with --tabsize and no/malformed argument

2020-04-27T22:50:08Z

--tabsize was previously listed as optional_argument, but didn't account for the optionality of it in the argument handling. This is irrelevant -- the manpage doesn't indicate that the argument is optional, and indeed there's no clear interpretation of omitting the argument because there's no other side effect of --tabsize. The "malformed" argument part of the header on this message is simply referring to usage like this: % diff --tabsize 4 A B With an optional_argument, the argument must be attached to the parameter directly (e.g. --tabsize=4), so the argument is effectively NULL with the above invocation as if no argument had been passed. PR: 243974

MFC r356723-r356725, r357649, r357652: diff(1) catch-up

2020-04-27T22:33:32Z

r356723: mkstemp returns -1 r356724: asprintf returns -1, not an arbitrary value < 0. Also upon error the (very sloppy specification) leaves an undefined value in *ret, so it is wrong to inspect it, the error condition is enough. r356725: When system calls indicate an error they return -1, not some arbitrary value < 0. errno is only updated in this case. r357649: Update diff(1) TODO removing what has been implemented r357652: Fix most of the style warnings

MFC r357648:

2020-03-04T11:28:49Z

diff: implement -y (--side-by-side) along with -W and --suppress-common-lines PR: 219933 Submitted by: fehmi noyan isi

diff(1): Implement -B/--ignore-blank-lines

2018-08-19T03:57:20Z

As noted by cem in r338035, coccinelle invokes diff(1) with the -B flag. This was not previously implemented here, so one was forced to create a link for GNU diff to /usr/local/bin/diff Implement the -B flag and add some primitive tests for it. It is implemented in the same fashion that -I is implemented; each chunk's lines are scanned, and if a non-blank line is encountered then the chunk will be output. Otherwise, it's skipped. MFC after: 2 weeks

Cross reference pr(1) which diff might call with -l option

2017-04-20T19:14:52Z

Document all long options

2017-04-20T19:05:43Z

Implement a basic --changed-group-format

2017-04-20T14:22:33Z

etcupdate(8) requires that option, while GNU diff supports many more variation of that options, their behaviour beside the simple verion implemented here are quite inconsistent as such I do not plan to implement those. The only special keyword supported by this implementation are: %< and %> %= is not implemented as the documentation of GNU diff says: common lines, but it actually when tested print the changes from the first file

add a stub --speed-large-files for compatibility with GNU diff

2017-04-08T08:46:02Z

There is no intention to implement it, but lots of scripts/tools using diff(1) passes GNU diff option

diff(1): document remaining long options

2017-03-23T04:35:52Z

While here, try and tie together some of the short options with their long option equivalents, where possible. Sponsored by: Dell EMC Isilon

diff(1): fix SYNOPSIS section noting non-existent option, --no-ignore-case

2017-03-22T18:13:14Z

`--no-ignore-case` should be `--no-ignore-file-name-case` per code for compatibility with [g]diff(1). Sponsored by: Dell EMC Isilon