fish-shell/tests/checks/redirect.fish
Fabian Boehm 20243132fb Add <? input redirection
This tries to open the given file to use as stdin, and if it fails,
for any reason, it uses /dev/null instead.

This is useful in cases where we would otherwise do either of these:

```fish
test -r /path/to/file
and string match foo < /path/to/file

cat /path/to/file 2>/dev/null | string match foo
```

This both makes it nicer and shorter, *and* helps with TOCTTOU - what if the file is removed/changed after the check?

The reason for reading /dev/null instead of a closed fd is that a closed fd will often cause an error.

In case opening /dev/null fails, it still skips the command.
That's really a last resort for when the operating system
has turned out to be a platypus and not a unix.

Fixes #4865

(cherry picked from commit df8b9b7095)
2024-04-21 14:35:13 +02:00

166 lines
4.2 KiB
Fish

#RUN: %fish %s
function outnerr
command echo out $argv
command echo err $argv 1>&2
end
outnerr 0 &| count
#CHECK: 2
outnerr appendfd 2>>&1
#CHECK: out appendfd
#CHECK: err appendfd
set -l tmpdir (mktemp -d)
outnerr overwrite &>$tmpdir/file.txt
cat $tmpdir/file.txt
#CHECK: out overwrite
#CHECK: err overwrite
outnerr append &>>$tmpdir/file.txt
cat $tmpdir/file.txt
#CHECK: out overwrite
#CHECK: err overwrite
#CHECK: out append
#CHECK: err append
echo noclobber &>>?$tmpdir/file.txt
#CHECKERR: {{.*}} The file {{.*}} already exists
eval "echo foo |& false"
#CHECKERR: {{.*}} |& is not valid. In fish, use &| to pipe both stdout and stderr.
#CHECKERR: echo foo |& false
#CHECKERR: ^^
# Ensure that redirection empty data still creates the file.
rm -f $tmpdir/file.txt
test -f $tmpdir/file.txt && echo "File exists" || echo "File does not exist"
#CHECK: File does not exist
echo -n >$tmpdir/file.txt
test -f $tmpdir/file.txt && echo "File exists" || echo "File does not exist"
#CHECK: File exists
rm $tmpdir/file.txt
echo -n 2>$tmpdir/file.txt
test -f $tmpdir/file.txt && echo "File exists" || echo "File does not exist"
#CHECK: File exists
rm $tmpdir/file.txt
function redir_to_argv1
if set -q argv[1]
redir_to_argv1 >$argv[1]
end
echo foo
end
redir_to_argv1 $tmpdir/bar
# CHECK: foo
cat $tmpdir/bar
# CHECK: foo
rm $tmpdir/bar
# Verify that we can turn stderr into stdout and then pipe it
# Note that the order here has historically been unspecified - 'errput' could conceivably appear before 'output'.
begin
echo output
echo errput 1>&2
end 2>&1 | sort | tee $tmpdir/tee_test.txt
cat $tmpdir/tee_test.txt
rm $tmpdir/tee_test.txt
rmdir $tmpdir
#CHECK: errput
#CHECK: output
#CHECK: errput
#CHECK: output
# Test that trailing ^ doesn't trigger redirection, see #1873
echo caret_no_redirect 12345^
#CHECK: caret_no_redirect 12345^
# Verify that we can pipe something other than stdout
# The first line should be printed, since we output to stdout but pipe stderr to /dev/null
# The second line should not be printed, since we output to stderr and pipe it to /dev/null
begin
echo is_stdout
end 2>| cat >/dev/null
begin
echo is_stderr 1>&2
end 2>| cat >/dev/null
#CHECK: is_stdout
# Verify builtin behavior with closed stdin.
# count silently ignores closed stdin, others may print an error.
true <&-
echo $status
#CHECK: 0
test -t 0 <&-
echo $status
#CHECK: 1
read abc <&-
#CHECKERR: read: stdin is closed
# This one should output nothing.
echo derp >&-
# Redirection to 0, 1, 2 should always work. We don't test 0 since writing to stdin is weird and unpredictable.
echo hooray1 >&1
echo hooray2 >&2
#CHECK: hooray1
#CHECKERR: hooray2
# "Verify that pipes don't conflict with fd redirections"
# This code is very similar to eval. We go over a bunch of fads
# to make it likely that we will nominally conflict with a pipe
# fish is supposed to detect this case and dup the pipe to something else
echo "/bin/echo pipe 3 <&3 3<&-" | source 3<&0
echo "/bin/echo pipe 4 <&4 4<&-" | source 4<&0
echo "/bin/echo pipe 5 <&5 5<&-" | source 5<&0
echo "/bin/echo pipe 6 <&6 6<&-" | source 6<&0
echo "/bin/echo pipe 7 <&7 7<&-" | source 7<&0
echo "/bin/echo pipe 8 <&8 8<&-" | source 8<&0
echo "/bin/echo pipe 9 <&9 9<&-" | source 9<&0
echo "/bin/echo pipe 10 <&10 10<&-" | source 10<&0
echo "/bin/echo pipe 11 <&11 11<&-" | source 11<&0
echo "/bin/echo pipe 12 <&12 12<&-" | source 12<&0
#CHECK: pipe 3
#CHECK: pipe 4
#CHECK: pipe 5
#CHECK: pipe 6
#CHECK: pipe 7
#CHECK: pipe 8
#CHECK: pipe 9
#CHECK: pipe 10
#CHECK: pipe 11
#CHECK: pipe 12
echo foo >/bin/echo/file
#CHECKERR: warning: An error occurred while redirecting file '/bin/echo/file'
#CHECKERR: warning: Path '/bin/echo' is not a directory
echo foo <?nonexistent
#CHECK: foo
echo $status
#CHECK: 0
read -l foo <?nonexistent
echo $status
#CHECK: 1
set -S foo
#CHECK: $foo: set in local scope, unexported, with 0 elements
set -l fish (status fish-path)
$fish --no-config -c 'true <&?fail'
#CHECKERR: fish: Requested redirection to '?fail', which is not a valid file descriptor
#CHECKERR: true <&?fail
#CHECKERR: ^~~~~~^
$fish --no-config -c 'true <?&fail'
#CHECKERR: fish: Expected a string, but found a '&'
#CHECKERR: true <?&fail
#CHECKERR: ^