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author | ridiculousfish <corydoras@ridiculousfish.com> | 2013-08-18 16:55:01 -0700 |
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committer | ridiculousfish <corydoras@ridiculousfish.com> | 2013-08-19 18:06:24 -0700 |
commit | e849beabbab31c83ac57693cb0a7ac1e58f8cfd5 (patch) | |
tree | fa8872516ac378bd32ef3be5844100bc64cf4c1b /share | |
parent | 2979d3bf169f51fb2ba218897994745754f830f9 (diff) |
Initial work towards various IO cleanups with an eye to fixing https://github.com/fish-shell/fish-shell/issues/110
Diffstat (limited to 'share')
-rw-r--r-- | share/functions/eval.fish | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/share/functions/eval.fish b/share/functions/eval.fish index 19f20731..939b17c9 100644 --- a/share/functions/eval.fish +++ b/share/functions/eval.fish @@ -19,6 +19,19 @@ function eval -S -d "Evaluate parameters as a command" status --job-control full end + # rfish: To eval 'foo', we construct a block "begin ; foo; end <&3 3<&-" + # The 'eval2_inner' is a param to 'begin' itself; I believe it does nothing. + # Note the redirections are also within the quotes. + # + # We then pipe this to 'source 3<&0' which dup2's 3 to stdin. + # + # You might expect that the dup2(3, stdin) should overwrite stdin, + # and therefore prevent 'source' from reading the piped-in block. This doesn't happen + # because when you pipe to a builtin, we don't overwrite stdin with the read end + # of the block; instead we set a separate fd in a variable 'builtin_stdin', which is + # what it reads from. So builtins are magic in that, in pipes, their stdin + # is not fd 0. + echo "begin; $argv "\n" ;end eval2_inner <&3 3<&-" | source 3<&0 set -l res $status |