[bug #56764] Different behavior of printf command executed from Makefile and from shell.

[Martin Dorey]

Follow-up Comment #3, bug #56764 (project make):

[comment #2 comment #2:]
> When make invokes printf it's assuming a POSIX shell, and running the
/usr/bin/printf executable not the bash builtin.

Look ma, no /usr/bin/printf:


mad@shuttle:~/tmp/make-56764$ strace -f make 2>&1 | grep exec
execve("/usr/bin/make", ["make"], [/* 42 vars */]) = 0
[pid 31739] execve("/bin/sh", ["/bin/sh", "-c", "printf '\\x00\\x00\\x8f\\x60'
> gene"...], [/* 45 vars */] <unfinished ...>
[pid 31739] <... execve resumed> )      = 0
mad@shuttle:~/tmp/make-56764$ hexdump -C generated_file.bin 
00000000  5c 78 30 30 5c 78 30 30  5c 78 38 66 5c 78 36 30 
|\x00\x00\x8f\x60|
00000010
mad@shuttle:~/tmp/make-56764$ 


That's using exactly the OP's makefile.  If I'd have been posting the bug
report, I'd have written the makefile on one line, to avoid problems with tabs
in emails:


mad@shuttle:~/tmp/make-56764$ cat Makefile.martind 
generated_file: ; @printf '\x00\x00\x8f\x60'
mad@shuttle:~/tmp/make-56764$ make -f Makefile.martind | hexdump -C
00000000  00 00 8f 60                                       |...`|
00000004
mad@shuttle:~/tmp/make-56764$ 


Oh dear, the problem's gone away, but what's this:


mad@shuttle:~/tmp/make-56764$ strace -f make -f Makefile.martind 2>&1 | grep
exec
execve("/usr/bin/make", ["make", "-f", "Makefile.martind"], [/* 42 vars */]) =
0
[pid 31938] execve("/usr/local/bin/printf", ["printf",
"\\x00\\x00\\x8f\\x60"], [/* 45 vars */]) = -1 ENOENT (No such file or
directory)
[pid 31938] execve("/usr/bin/printf", ["printf", "\\x00\\x00\\x8f\\x60"], [/*
45 vars */]) = 0
mad@shuttle:~/tmp/make-56764$ 


Now it's executed /usr/bin/printf, as Paul suggested it would, but, on this
computer, Debian Stretch's coreutils' /usr/bin/printf supports these
non-standard escapes.  I think it's the OP's > which stops make from executing
/usr/bin/printf directly.

I have no dispute with anything else Paul wrote.  Ugh, octal, I wish we could
let the 1970s go.

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