diff options
author | Matthew DeVore <matvore@google.com> | 2018-10-06 00:54:02 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2018-10-07 02:51:17 +0300 |
commit | a378fee5b0795d671722d803b93b7b32941c0067 (patch) | |
tree | 67b3d1b032b4de9f14749ed7e1c31c9b6e963f12 /t | |
parent | 441ee35d8384fe7f6328584ac1634da14ed42e11 (diff) |
Documentation: add shell guidelines
Add the following guideline to Documentation/CodingGuidelines:
Break overlong lines after "&&", "||", and "|", not before
them; that way the command can continue to subsequent lines
without backslash at the end.
And the following to t/README (since it is specific to writing tests):
Pipes and $(git ...) should be avoided when they swallow exit
codes of Git processes
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't')
-rw-r--r-- | t/README | 27 |
1 files changed, 27 insertions, 0 deletions
@@ -474,6 +474,33 @@ And here are the "don'ts:" platform commands; just use '! cmd'. We are not in the business of verifying that the world given to us sanely works. + - Don't feed the output of a git command to a pipe, as in: + + git -C repo ls-files | + xargs -n 1 basename | + grep foo + + which will discard git's exit code and may mask a crash. In the + above example, all exit codes are ignored except grep's. + + Instead, write the output of that command to a temporary + file with ">" or assign it to a variable with "x=$(git ...)" rather + than pipe it. + + - Don't use command substitution in a way that discards git's exit + code. When assigning to a variable, the exit code is not discarded, + e.g.: + + x=$(git cat-file -p $sha) && + ... + + is OK because a crash in "git cat-file" will cause the "&&" chain + to fail, but: + + test "refs/heads/foo" = "$(git symbolic-ref HEAD)" + + is not OK and a crash in git could go undetected. + - Don't use perl without spelling it as "$PERL_PATH". This is to help our friends on Windows where the platform Perl often adds CR before the end of line, and they bundle Git with a version of Perl that |