Bug#592519: $COMPRESS/$compress does not accept arguments

["Trent W. Buck" <trentbuck@gmail.com>]

Hi,

I wanted to say pass options to my compress program, e.g.

    # cat /etc/initramfs-tools/conf.d/xz
    compress="pxz -Ccrc32 -1"       # dev builds should build fast
    compress="pxz -Ccrc32 -9ev"     # prod builds should boot fast

Unfortunately this code requires the compress (or COMPRESS) be a program,
not a program-plus-options:

    2010-07-05 mat 3bdc6b1 if ! command -v "${compress}" >/dev/null 2>&1; then
    2010-02-28 bsc 38c90c5         compress=gzip
    2010-02-28 bsc 38c90c5         [ "${verbose}" = y ] && \
    2010-02-28 bsc 38c90c5                 echo "No ${COMPRESS} in ${PATH}, using gzip"
    2011-01-25 GTi 9c25269         COMPRESS=gzip
    2010-02-28 bsc 38c90c5 fi

This results in:

    No xz --check=crc32 -1 in /usr/bin:/sbin:/bin, using gzip

This is incredibly annoying, because immediately AFTER that test,
compress gets used in exactly the way I want:

    2010-04-09 bsc 3041c94 [ "${compress}" = lzop ] && compress="lzop -9"
    2014-10-16 BHu cf9691d [ "${compress}" = xz ] && compress="xz --check=crc32"

A yukky kludge is to strip everything after a space (but not tab &c):

    - if ! command -v "${compress}" >/dev/null 2>&1; then
    + if ! command -v "${compress%% *}" >/dev/null 2>&1; then

Another approach would just be to run the command with --help, or dummy data:

    - if ! command -v "${compress}" >/dev/null 2>&1; then
    + if ! "$compress" </dev/null >/dev/null 2>&1; then

If $? is 127, then it's not in $PATH.


In the meantime, I can work around this by creating a wrapper script:

    >/ARGH.sh  printf '#!/bin/sh\nexec pxz -Ccrc32 -9ev\n'
    chmod +x /ARGH.sh
    >/etc/initramfs-tools/conf.d/xz echo COMPRESS=/ARGH.sh
    update-initramfs -u -k all

...but this makes me sad.