When IMPORT{program} output was truncated, the code intended to drop
the last incomplete result line before importing properties.
It edited the command buffer instead of the output buffer, so the
incomplete line could still be parsed and imported.
Trim the result buffer and cover the behavior with the existing IMPORT
test.
Follow-up for 6b6e471a32.
Reproducer:
Configure an IMPORT{program} rule whose output exceeds UDEV_LINE_SIZE
and ends with an incomplete property line, for example:
TRUNCATED_OK=yes
TRUNCATED_BAD=<very long value without terminating newline>
Only TRUNCATED_OK should be imported. Before this fix, the truncation
handler edited the command buffer instead of the output buffer, so
TRUNCATED_BAD could still be parsed from the truncated result.
When a TTY is attached to the test unit, grep -q will generate SIGPIPE
for the previous command in the pipeline which in combo with `pipefail`
will cause the command to fail with exit status 141 which will fail the
test.
Replace with >/dev/null to avoid this from happening.
See also https://www.gnu.org/software/grep/manual/html_node/Usage.html
> There is a related problem with Bash’s set -e -o pipefail. Since grep
> does not always read all its input, a command outputting to a pipe read
> by grep can fail when grep exits before reading all its input, and the
> command’s failure can cause Bash to exit.
Co-authored-by: Yu Watanabe <watanabe.yu+github@gmail.com>
This also makes shebang always use env command, and drops unnecessary
'bash -c' or 'sh -c' when a signle command is invoked in the shell,
like sleep or echo.