[PATCH] treewide: replace `which` with `command -v`

Paul Spooren mail at aparcar.org
Fri Aug 7 20:42:25 EDT 2020


On 07.08.20 14:18, Rosen Penev wrote:
> On Fri, Aug 7, 2020 at 3:57 PM Paul Spooren <mail at aparcar.org> wrote:
>> Fix shellcheck SC2230
>>> which is non-standard. Use builtin 'command -v' instead.
>> Once applied to everything concerning OpenWrt we can disable the busybox
>> feature `which` and save 3.8kB.
> which and command -v seem to not be the same. See
> https://github.com/openwrt/openwrt/commit/8242c6de29951fbb549355770cd685ffe3ac9c54

Afaik ldir uses a Mac which may has a different build in implementation 
of `command`.

Testing it locally on a Linux machine they behave very much the same.

user at dawn:~/src/openwrt/openwrt$ command -v git
/usr/bin/git
user at dawn:~/src/openwrt/openwrt$ which git
/usr/bin/git
user at dawn:~/src/openwrt/openwrt$ command -v git-nope
user at dawn:~/src/openwrt/openwrt$ echo $?
1
user at dawn:~/src/openwrt/openwrt$ which git-nope
user at dawn:~/src/openwrt/openwrt$ echo $?
1

I'd image the *command* `command` doesn't exist on a Mac and it would 
actually execute the *command* `git` there, which obviously pollutes the 
output.

Seems like a problem of Mac and not the bash/sh included `command`. 
Thinking about that, it seems fairly dangerous: If you'd run `command -v 
nuke_harddrive > /dev/null` it would actually run whatever command silently.

There is a wrapper called `./scripts/md5sum` which calls `md5`, the Mac 
tool to get a MD5 checksum.

I guess we could create a wrapper like ./scripts/command which contains 
the following line:

which $2 # skipping the -v arg of command

Ultimately it's about freeing up busybox-which, which is independent of 
any Mac ideas. For that rootfs.mk and ipkg-build could be left untouched.

>> Signed-off-by: Paul Spooren <mail at aparcar.org>
>> ---
>>   include/rootfs.mk                                    |  6 +++---
>>   package/base-files/files/lib/upgrade/stage2          |  2 +-
>>   .../kernel/broadcom-wl/files/lib/wifi/broadcom.sh    |  2 +-
>>   scripts/ipkg-build                                   | 12 ++++++------
>>   4 files changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/include/rootfs.mk b/include/rootfs.mk
>> index b6775c7e15..18ada3cd43 100644
>> --- a/include/rootfs.mk
>> +++ b/include/rootfs.mk
>> @@ -69,7 +69,7 @@ define prepare_rootfs
>>          @( \
>>                  cd $(1); \
>>                  for script in ./usr/lib/opkg/info/*.postinst; do \
>> -                       IPKG_INSTROOT=$(1) $$(which bash) $$script; \
>> +                       IPKG_INSTROOT=$(1) $$(command -v bash) $$script; \
>>                          ret=$$?; \
>>                          if [ $$ret -ne 0 ]; then \
>>                                  echo "postinst script $$script has failed with exit code $$ret" >&2; \
>> @@ -79,10 +79,10 @@ define prepare_rootfs
>>                  for script in ./etc/init.d/*; do \
>>                          grep '#!/bin/sh /etc/rc.common' $$script >/dev/null || continue; \
>>                          if ! echo " $(3) " | grep -q " $$(basename $$script) "; then \
>> -                               IPKG_INSTROOT=$(1) $$(which bash) ./etc/rc.common $$script enable; \
>> +                               IPKG_INSTROOT=$(1) $$(command -v bash) ./etc/rc.common $$script enable; \
>>                                  echo "Enabling" $$(basename $$script); \
>>                          else \
>> -                               IPKG_INSTROOT=$(1) $$(which bash) ./etc/rc.common $$script disable; \
>> +                               IPKG_INSTROOT=$(1) $$(command -v bash) ./etc/rc.common $$script disable; \
>>                                  echo "Disabling" $$(basename $$script); \
>>                          fi; \
>>                  done || true \
>> diff --git a/package/base-files/files/lib/upgrade/stage2 b/package/base-files/files/lib/upgrade/stage2
>> index dbb33e8958..a4fef42134 100755
>> --- a/package/base-files/files/lib/upgrade/stage2
>> +++ b/package/base-files/files/lib/upgrade/stage2
>> @@ -45,7 +45,7 @@ switch_to_ramfs() {
>>                  snapshot snapshot_tool                                  \
>>                  $RAMFS_COPY_BIN
>>          do
>> -               local file="$(which "$binary" 2>/dev/null)"
>> +               local file="$(command -v "$binary" 2>/dev/null)"
>>                  [ -n "$file" ] && install_bin "$file"
>>          done
>>          install_file /etc/resolv.conf /lib/*.sh /lib/functions/*.sh /lib/upgrade/*.sh /lib/upgrade/do_stage2 /usr/share/libubox/jshn.sh $RAMFS_COPY_DATA
>> diff --git a/package/kernel/broadcom-wl/files/lib/wifi/broadcom.sh b/package/kernel/broadcom-wl/files/lib/wifi/broadcom.sh
>> index 33447341b2..352c365f27 100644
>> --- a/package/kernel/broadcom-wl/files/lib/wifi/broadcom.sh
>> +++ b/package/kernel/broadcom-wl/files/lib/wifi/broadcom.sh
>> @@ -223,7 +223,7 @@ enable_broadcom() {
>>          }
>>
>>          local _c=0
>> -       local nas="$(which nas)"
>> +       local nas="$(command -v nas)"
>>          local if_pre_up if_up nas_cmd
>>          local vif vif_pre_up vif_post_up vif_do_up vif_txpower
>>          local bssmax=$(wlc ifname "$device" bssmax)
>> diff --git a/scripts/ipkg-build b/scripts/ipkg-build
>> index 21127f3391..6e027bc546 100755
>> --- a/scripts/ipkg-build
>> +++ b/scripts/ipkg-build
>> @@ -10,10 +10,10 @@
>>   set -e
>>
>>   version=1.0
>> -FIND="$(which find)"
>> -FIND="${FIND:-$(which gfind)}"
>> -TAR="${TAR:-$(which tar)}"
>> -GZIP="$(which gzip)"
>> +FIND="$(command -v find)"
>> +FIND="${FIND:-$(command -v gfind)}"
>> +TAR="${TAR:-$(command -v tar)}"
>> +GZIP="$(command -v gzip)"
>>
>>   # try to use fixed source epoch
>>   if [ -n "$SOURCE_DATE_EPOCH" ]; then
>> @@ -21,10 +21,10 @@ if [ -n "$SOURCE_DATE_EPOCH" ]; then
>>
>>   # look up date of last commit
>>   elif [ -d "$TOPDIR/.git" ]; then
>> -       GIT="$(which git)"
>> +       GIT="$(command -v git)"
>>          TIMESTAMP=$(cd $TOPDIR; $GIT log -1 -s --format=%ci)
>>   elif [ -d "$TOPDIR/.svn" ]; then
>> -       SVN="$(which svn)"
>> +       SVN="$(command -v svn)"
>>          TIMESTAMP=$($SVN info "$TOPDIR" | sed -n "s/^Last Changed Date: \(.*\)/\1/p")
>>   else
>>          TIMESTAMP=$(date)
>> --
>> 2.25.1
>>
>>
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>> openwrt-devel at lists.openwrt.org
>> https://lists.openwrt.org/mailman/listinfo/openwrt-devel



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