I try to print to STDOUT the 0x09 (horizontal TAB) value, but in perl, python or bash 0x09 is replaced by 0x20 (a space).
$ hexdump -C <<< $(perl -e 'print "A\x09B" ')
00000000 41 20 42 0a |A B.|
00000004
same problem in bash:
$ hexdump -C <<< $(printf "A\x09B")
00000000 41 20 42 0a |A B.|
00000004
It's possible to print the 0x09 value to STDOUT?
At issue here is Bash expansion ; you get the same issue with putting the command in backticks:
$ echo `python -c 'print "A\x09B"'`
A B
Avoid expansion; it splits your input on whitespace and rejoins for the next command; you see the same with multiple spaces:
$ hexdump -C <<< $(python -c 'print "A\x20\x20\x20B"')
00000000 41 20 42 0a |A B.|
00000004
Use a pipe instead:
$ python -c 'print "A\x09B"' | hexdump
0000000 41 09 42 0a
0000004
or quote the command (miraculously, the extra quotes don't clash with those used in the command line itself!):
hexdump -C <<< "$(python -c 'print "A\x20\x20\x20B"')"
The subprocess output being expanded is a bug in bash, to be fixed in bash 4.4.
It's entirely a bash issue. Specifically, it's a bash bug that can be worked around as follows:
+-------- Add these ---------+
| |
v v
$ hexdump -C <<< "$(perl -e 'print "A\x09B"' )"
00000000 41 09 42 0a |A.B.|
00000004
Alternatively,
# Passed via STDIN as the original.
$ perl -e 'print "A\x09B"' | hexdump -C
00000000 41 09 42 |A.B|
00000003
# Passed via a file name.
$ hexdump -C <( perl -e 'print "A\x09B"' )
00000000 41 09 42 |A.B|
00000003
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