[PATCH v3] Fix cp's target path for ext* filesystems

[PATCH v3] Fix cp's target path for ext* filesystems

[Leonardo Augusto]

Python subprocess' shell=True defaults to /bin/sh[1][2], which
often refers to a POSIX-compliant shell. As the -e flag is
not defined in the POSIX standard[3], some shells may
interpret "-e" as the first argument to the echo command,
causing the rest of the command line to fail.

In this particular case, "echo -e 'cd {}'" is interpreted
as "-e cd {}", which causes the first line of the command
to fail, and causing cp to always place the source file
in the filesystem's root.

Replacing "echo -e" for a printf command makes this
more portable.

This issue only affects "wic cp" for ext* filesystems.

[1] https://docs.python.org/2/library/subprocess.html
[2] https://docs.python.org/3/library/subprocess.html
[3] http://pubs.opengroup.org/onlinepubs/9699919799

Signed-off-by: Leonardo Augusto <leobsd@gmail.com>
---
 scripts/lib/wic/engine.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/lib/wic/engine.py b/scripts/lib/wic/engine.py
index 4662c665c0..97f5e848cc 100644
--- a/scripts/lib/wic/engine.py
+++ b/scripts/lib/wic/engine.py
@@ -331,7 +331,7 @@ class Disk:
     def copy(self, src, pnum, path):
         """Copy partition image into wic image."""
         if self.partitions[pnum].fstype.startswith('ext'):
-            cmd = "echo -e 'cd {}\nwrite {} {}' | {} -w {}".\
+            cmd = "printf 'cd {}\nwrite {} {}' | {} -w {}".\
                       format(path, src, os.path.basename(src),
                              self.debugfs, self._get_part_image(pnum))
         else: # fat
-- 
2.17.1

Re: [PATCH v3] Fix cp's target path for ext* filesystems

[Leonardo Rangel]

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Does anybody have other suggestions on this one?

> Python subprocess' shell=True defaults to /bin/sh[1][2], which
> often refers to a POSIX-compliant shell. As the -e flag is
> not defined in the POSIX standard[3], some shells may
> interpret "-e" as the first argument to the echo command,
> causing the rest of the command line to fail.
>
> In this particular case, "echo -e 'cd {}'" is interpreted
> as "-e cd {}", which causes the first line of the command
> to fail, and causing cp to always place the source file
> in the filesystem's root.
>
> Replacing "echo -e" for a printf command makes this
> more portable.
>
> This issue only affects "wic cp" for ext* filesystems.
>
> [1] https://docs.python.org/2/library/subprocess.html
> [2] https://docs.python.org/3/library/subprocess.html
> [3] http://pubs.opengroup.org/onlinepubs/9699919799
>
> Signed-off-by: Leonardo Augusto <leobsd@gmail.com>
> ---
>  scripts/lib/wic/engine.py | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/lib/wic/engine.py b/scripts/lib/wic/engine.py
> index 4662c665c0..97f5e848cc 100644
> --- a/scripts/lib/wic/engine.py
> +++ b/scripts/lib/wic/engine.py
> @@ -331,7 +331,7 @@ class Disk:
>      def copy(self, src, pnum, path):
>          """Copy partition image into wic image."""
>          if self.partitions[pnum].fstype.startswith('ext'):
> -            cmd = "echo -e 'cd {}\nwrite {} {}' | {} -w {}".\
> +            cmd = "printf 'cd {}\nwrite {} {}' | {} -w {}".\
>                        format(path, src, os.path.basename(src),
>                               self.debugfs, self._get_part_image(pnum))
>          else: # fat

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Re: [PATCH v3] Fix cp's target path for ext* filesystems

[Richard Purdie]

On Fri, 2019-02-15 at 23:39 -0800, Leonardo Rangel wrote:
> Does anybody have other suggestions on this one?

It merged:

http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=89d4a8df074598cfb3a76e41db7c45d845afd961

Cheers,

Richard