Re: [pacman-dev] [PATCH v3 1/2] libmakepkg: extend compress.sh to also permit checking validity

2020-08-09 Thread Allan McRae
On 6/8/20 12:02 am, Eli Schwartz wrote:
> get_compression_command() can now be used to do upfront checks for
> whether a given extension is known to do something successfully. This is
> useful when writing tools in which an unknown compression type is a
> fatal error.
> 
> Signed-off-by: Eli Schwartz 
> ---
> 
> v3: split commit, this first part implements a function useful for
> checking if we have a known good compression type
> 

I'm happy with this and the following patch.

A


[pacman-dev] [PATCH v3 1/2] libmakepkg: extend compress.sh to also permit checking validity

2020-08-05 Thread Eli Schwartz
get_compression_command() can now be used to do upfront checks for
whether a given extension is known to do something successfully. This is
useful when writing tools in which an unknown compression type is a
fatal error.

Signed-off-by: Eli Schwartz 
---

v3: split commit, this first part implements a function useful for
checking if we have a known good compression type

 scripts/libmakepkg/util/compress.sh.in | 53 +++---
 1 file changed, 40 insertions(+), 13 deletions(-)

diff --git a/scripts/libmakepkg/util/compress.sh.in 
b/scripts/libmakepkg/util/compress.sh.in
index 16420beb..d35a01fa 100644
--- a/scripts/libmakepkg/util/compress.sh.in
+++ b/scripts/libmakepkg/util/compress.sh.in
@@ -24,6 +24,7 @@ LIBMAKEPKG_UTIL_COMPRESS_SH=1
 LIBRARY=${LIBRARY:-'@libmakepkgdir@'}
 
 source "$LIBRARY/util/message.sh"
+source "$LIBRARY/util/pkgbuild.sh"
 
 
 # Wrapper around many stream compression formats, for use in the middle of a
@@ -31,20 +32,46 @@ source "$LIBRARY/util/message.sh"
 compress_as() {
# $1: final archive filename extension for compression type detection
 
-   local ext=".tar${1##*.tar}"
+   local cmd ext=${1#${1%.tar*}}
+
+   if ! get_compression_command "$ext" cmd; then
+   warning "$(gettext "'%s' is not a valid archive extension.")" 
"${ext:-${1##*/}}"
+   cat
+   else
+   "${cmd[@]}"
+   fi
+}
+
+# Retrieve the compression command for an archive extension, or cat for .tar,
+# and save it to an existing array name. If the extension cannot be found,
+# clear the array and return failure.
+get_compression_command() {
+   local extarray ext=$1 outputvar=$2
+   local resolvecmd=() fallback=()
 
case "$ext" in
-   *.tar.gz)  ${COMPRESSGZ[@]:-gzip -c -f -n} ;;
-   *.tar.bz2) ${COMPRESSBZ2[@]:-bzip2 -c -f} ;;
-   *.tar.xz)  ${COMPRESSXZ[@]:-xz -c -z -} ;;
-   *.tar.zst) ${COMPRESSZST[@]:-zstd -c -z -q -} ;;
-   *.tar.lrz) ${COMPRESSLRZ[@]:-lrzip -q} ;;
-   *.tar.lzo) ${COMPRESSLZO[@]:-lzop -q} ;;
-   *.tar.Z)   ${COMPRESSZ[@]:-compress -c -f} ;;
-   *.tar.lz4) ${COMPRESSLZ4[@]:-lz4 -q} ;;
-   *.tar.lz)  ${COMPRESSLZ[@]:-lzip -c -f} ;;
-   *.tar) cat ;;
-   *) warning "$(gettext "'%s' is not a valid archive 
extension.")" \
-   "$ext"; cat ;;
+   *.tar.gz)  fallback=(gzip -c -f -n) ;;
+   *.tar.bz2) fallback=(bzip2 -c -f) ;;
+   *.tar.xz)  fallback=(xz -c -z -) ;;
+   *.tar.zst) fallback=(zstd -c -z -q -) ;;
+   *.tar.lrz) fallback=(lrzip -q) ;;
+   *.tar.lzo) fallback=(lzop -q) ;;
+   *.tar.Z)   fallback=(compress -c -f) ;;
+   *.tar.lz4) fallback=(lz4 -q) ;;
+   *.tar.lz)  fallback=(lzip -c -f) ;;
+   *.tar) fallback=(cat) ;;
+   # do not respect unknown COMPRESS* env vars
+   *)array_build "$outputvar" resolvecmd; return 1 ;;
esac
+
+   ext=${ext#*.tar.}
+   if [[ -n $ext ]]; then
+   extarray="COMPRESS${ext^^}[@]"
+   resolvecmd=("${!extarray}")
+   fi
+   if (( ${#resolvecmd[@]} == 0 )); then
+   resolvecmd=("${fallback[@]}")
+   fi
+
+   array_build "$outputvar" resolvecmd
 }
-- 
2.28.0