mirror_zfs/cmd
Graham Christensen dda702fd16
bash scripts: use /usr/bin/env for bash shebangs
Not all systems / distros have a `/bin/bash`, and these scripts are
more difficult to run at development time.

For example, my system is NixOS which doesn't have a /bin/bash. This
is not a problem for NixOS building ZFS as a package: the build
environment automatically replaces these shebangs with corrected
paths.

The problem is much more annoying at development time: either the
scripts don't run, or I correct them for my local machine and deal with
a perpetually dirty work tree.

Before committing this patch I confirmed there are existing scripts
which use `/usr/bin/env` to locate bash, so I am thinking this is a
safe transformation.

There are a handful of other shebangs in this repository which don't
work on my system. This patch is useful on its own specifically for
`commitcheck.sh`, otherwise I can't validate my commits before
submission.

Here are the remaining shebangs which NixOS systems won't have:

       1274 #!/bin/ksh -p
         91 #!/bin/ksh
         89 #! /bin/ksh -p
          2 #!/bin/sed -f
          1 #!/usr/bin/perl -w
          1 #!/usr/bin/ksh
          1 #!/bin/nawk -f

plus this which will create an invalid shebang in
`tests/zfs-tests/tests/functional/mv_files/mv_files_common.kshlib`:

        echo "#!/bin/ksh" > $TEST_BASE_DIR/exitsZero.ksh

I chose to leave those alone for now, and gauge the interest in this
much smaller patch first.

The fixes for these are easy enough by simply using `/usr/bin/env ksh`:

         91 #!/bin/ksh
          1 #!/usr/bin/ksh

The fix for the other set is much trickier. Quoting the GNU coreutils
manual:

    Most operating systems (e.g. GNU/Linux, BSDs) treat all text after
    the first space as a single argument. When using env in a script it
    is thus not possible to specify multiple arguments.

and not all `env`'s support arguments.

Mine (GNU Coreutils 8.31) does, though this feature is new since
April 2018, GNU Coreutils 8.30:
https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=668306ed86c8c79b0af0db8b9c882654ebb66db2

and worse, requires the -S argument:

    -S, --split-string=S  process and split S into separate arguments;
                          used to pass multiple arguments on shebang
                          lines

Example:

    $ seq 1 2 | $(nix-build '<nixpkgs>' -A coreutils)/bin/env "sort -nr"
    /nix/[...]-coreutils-8.31/bin/env: ‘sort -nr’: No such file or directory
    /nix/[...]-coreutils-8.31/bin/env: use -[v]S to pass options in shebang lines

    $ seq 1 2 | $(nix-build '<nixpkgs>' -A coreutils)/bin/env "-S sort -nr"
    2
    1

GNU Coreutils says FreeBSD's `env` does, though I wonder if FreeBSD's
would be unhappy with the `-S`:
https://www.gnu.org/software/coreutils/manual/html_node/env-invocation.html#env-invocation

BusyBox v1.30.1 does not, and does not have a `-S`-like option:

    $ seq 1 2 | $(nix-build '<nixpkgs>' -A busybox)/bin/env "sort -nr"
    env: can't execute 'sort -nr': No such file or directory

Toybox 0.8.1 also does not, and also does not have a `-S` option:

    $ seq 1 2 | $(nix-build '<nixpkgs>' -A toybox)/bin/env "sort -nr"
    env: exec sort -nr: No such file or directory

---

At any rate, if this patch merges and the remaining ~1,500 are updated,
the much larger patch should probably include a checkstyle-like test
asserting all new shebangs use `/usr/bin/env`. I also don't mind
dealing with NixOS weirdness if the project would prefer that.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Graham Christensen <graham@grahamc.com>
Closes #9893
2020-02-10 13:13:46 -08:00
..
arc_summary Fix reporting of L2ARC hits/misses in arc_summary3 2019-12-04 13:24:55 -08:00
arcstat Add FreeBSD code to arc_summary and arcstat 2019-11-30 15:43:23 -08:00
dbufstat Detect if sed supports --in-place 2019-10-16 19:19:48 -07:00
fsck_zfs Fix typos in cmd/ 2019-08-30 09:43:30 -07:00
mount_zfs OpenZFS restructuring - libspl 2019-10-02 10:39:48 -07:00
raidz_test Add AltiVec RAID-Z 2020-01-23 11:01:24 -08:00
vdev_id Fix typos in cmd/ 2019-08-30 09:43:30 -07:00
zdb zdb: add support for object ranges for zdb -d 2020-01-24 11:00:46 -08:00
zed OpenZFS restructuring - libzutil 2019-10-03 10:20:44 -07:00
zfs Fix static data to link with -fno-common 2020-02-06 09:25:29 -08:00
zgenhostid bash scripts: use /usr/bin/env for bash shebangs 2020-02-10 13:13:46 -08:00
zhack Add zfs_file_* interface, remove vnodes 2019-11-21 09:32:57 -08:00
zinject Remove ECKSUM alias in zinject 2019-11-01 10:31:42 -07:00
zpool Fix static data to link with -fno-common 2020-02-06 09:25:29 -08:00
zstreamdump OpenZFS restructuring - libspl 2019-10-02 10:39:48 -07:00
ztest Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
zvol_id OpenZFS restructuring - libspl 2019-10-02 10:39:48 -07:00
zvol_wait zvol_wait should ignore redacted zvols 2019-11-06 10:51:19 -08:00
Makefile.am Isolate code specific to Linux in cmd/ 2019-11-11 09:24:04 -08:00