Fix shellcheck version >= 0.5.0 errors

Summary:
The linter will throw warnings and errors with `shellcheck` versions >=
0.5.

Backport of core PR16327 (which implies PR14115, PR15164 and PR15166)
https://github.com/bitcoin/bitcoin/pull/16327/files

https://github.com/bitcoin/bitcoin/pull/14115/files
https://github.com/bitcoin/bitcoin/pull/15164/files
https://github.com/bitcoin/bitcoin/pull/15166/files

Note that the rule SC1117 (from PR14115) is still excluded as it would
throw false positives. It has been removed from `shellcheck` versions >
0.5.0, but I kept it for compatibility with previous versions (i.e.
Debian buster has 0.5.0).
See https://github.com/koalaman/shellcheck/wiki/SC1117 for details.

Test Plan:
Install the latest `shellcheck` (currently 0.7.0).
Check `arc lint --everything` returns no error.
Tested with versions 0.4.4, 0.4.6, 0.5.0 and 0.7.0.

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D3969

arcanist/.phutil_module_cache

@@ -1 +1 @@
-{"__symbol_cache_version__":11,"ae5b7d3d6b8cf9598ce4abaf0cd56b21":{"have":{"class":{"ExtendedConfigurationDrivenLintEngine":19}},"need":{"function":{"newv":159,"pht":933},"class":{"ArcanistLintEngine":65,"ArcanistConfigurationDrivenLintEngine":171,"PhutilConsole":866},"class\/interface":{"ILintOnce":634}},"xmap":{"ExtendedConfigurationDrivenLintEngine":["ArcanistLintEngine"]}},"2809b09d2021203b43c57da33d1fe8bf":{"have":{"class":{"AssertWithSideEffectsLinter":210}},"need":{"function":{"pht":439},"class":{"ArcanistLinter":246,"ArcanistLintSeverity":926,"Filesystem":1170}},"xmap":{"AssertWithSideEffectsLinter":["ArcanistLinter"]}},"90a8b110dc475955f15bb81d37268cb5":{"have":{"class":{"AutoPEP8FormatLinter":75}},"need":{"function":{"pht":297,"execx":769,"id":1903},"class":{"ArcanistExternalLinter":104,"ArcanistLintMessage":1910,"Filesystem":1754,"ArcanistLinter":2017,"ArcanistLintSeverity":2095}},"xmap":{"AutoPEP8FormatLinter":["ArcanistExternalLinter"]}},"5ea58c19df0397ed8ee0f463d90d6c72":{"have":{"class":{"BoostDependenciesLinter":145}},"need":{"function":{"pht":330,"id":1440},"class":{"GlobalExternalLinter":177,"ArcanistLintMessage":1447,"Filesystem":609,"ArcanistLinter":1524,"ArcanistLintSeverity":1624}},"xmap":{"BoostDependenciesLinter":["GlobalExternalLinter"]}},"38f0c676bff5192a344464142caaa253":{"have":{"class":{"CHeaderLinter":99}},"need":{"function":{"pht":611},"class":{"ArcanistLinter":121,"ArcanistLintSeverity":1060,"Filesystem":1307}},"xmap":{"CHeaderLinter":["ArcanistLinter"]}},"9bb48ec0fe2e9ced8e27d42540d0571c":{"have":{"class":{"CheckDocLinter":106}},"need":{"function":{"pht":321,"id":1845},"class":{"GlobalExternalLinter":129,"ArcanistLintMessage":1852,"Filesystem":729,"ArcanistLinter":1900,"ArcanistLintSeverity":1986}},"xmap":{"CheckDocLinter":["GlobalExternalLinter"]}},"63d19a8745cb2e1200cc26488dc7ad25":{"have":{"class":{"CheckRpcMappingsLinter":131}},"need":{"function":{"pht":310,"id":1386},"class":{"GlobalExternalLinter":162,"ArcanistLintMessage":1393,"Filesystem":573,"ArcanistLinter":1443,"ArcanistLintSeverity":1544}},"xmap":{"CheckRpcMappingsLinter":["GlobalExternalLinter"]}},"1c03a4631b02b8e1ebcc3a078dc1e4af":{"have":{"class":{"ClangFormatLinter":79}},"need":{"function":{"pht":302,"execx":781,"id":2235},"class":{"ArcanistExternalLinter":105,"ArcanistLintMessage":2242,"Filesystem":2086,"ArcanistLinter":2349,"ArcanistLintSeverity":2427}},"xmap":{"ClangFormatLinter":["ArcanistExternalLinter"]}},"75579a609dd975aa0226add52700c622":{"have":{"class":{"FileNameLinter":103}},"need":{"function":{"pht":307},"class":{"ArcanistLinter":126,"ArcanistLintSeverity":662,"Filesystem":968}},"xmap":{"FileNameLinter":["ArcanistLinter"]}},"9285ad9415f8ebe564f7119e5a72c559":{"have":{"class":{"FormatStringLinter":146}},"need":{"function":{"pht":377,"csprintf":1492,"id":1872},"class":{"ArcanistExternalLinter":173,"ArcanistLintMessage":1879,"Filesystem":827,"ArcanistLinter":1956,"ArcanistLintSeverity":2044}},"xmap":{"FormatStringLinter":["ArcanistExternalLinter"]}},"2e11dd9ad67e594f863bc46ac59ea37e":{"have":{"class":{"GlobalExternalLinter":199}},"need":{"class":{"ArcanistExternalLinter":228},"interface":{"ILintOnce":262}},"xmap":{"GlobalExternalLinter":["ArcanistExternalLinter","ILintOnce"]}},"b2403124ec3e8be6cb4d10bf0f6c4134":{"have":{"interface":{"ILintOnce":69}},"need":[],"xmap":[]},"1f9bac7956f4f948a187828dcc6ba2d0":{"have":{"class":{"IncludeGuardLinter":98}},"need":{"function":{"pht":368},"class":{"ArcanistLinter":125,"ArcanistLintSeverity":721,"Filesystem":970}},"xmap":{"IncludeGuardLinter":["ArcanistLinter"]}},"2cbb6e7228d81557f777ad648704f343":{"have":{"class":{"IncludeQuotesLinter":100}},"need":{"function":{"pht":306},"class":{"ArcanistLinter":128,"ArcanistLintSeverity":663,"Filesystem":964}},"xmap":{"IncludeQuotesLinter":["ArcanistLinter"]}},"f151089cf79fdb8257b2272ed4782d88":{"have":{"class":{"IncludeSourceLinter":99}},"need":{"function":{"pht":391},"class":{"ArcanistLinter":127,"ArcanistLintSeverity":699,"Filesystem":938}},"xmap":{"IncludeSourceLinter":["ArcanistLinter"]}},"8a0f2ba683e96feeb9d9564af01fe3e7":{"have":{"class":{"LocaleDependenceLinter":160}},"need":{"function":{"pht":5460},"class":{"ArcanistLinter":191,"ArcanistLintSeverity":5963,"Filesystem":6209}},"xmap":{"LocaleDependenceLinter":["ArcanistLinter"]}},"6f2f22dd0f259fb2eaa284b4fab3bc29":{"have":{"class":{"PythonFormatLinter":123}},"need":{"function":{"pht":353,"id":1838},"class":{"ArcanistExternalLinter":150,"ArcanistLintMessage":1845,"Filesystem":776,"ArcanistLinter":1970,"ArcanistLintSeverity":2053}},"xmap":{"PythonFormatLinter":["ArcanistExternalLinter"]}},"03cf226fe177a9fce7dc046816cc466b":{"have":{"class":{"PythonOpenFileEncodingLinter":111}},"need":{"function":{"pht":325},"class":{"ArcanistLinter":148,"ArcanistLintSeverity":687,"Filesystem":991}},"xmap":{"PythonOpenFileEncodingLinter":["ArcanistLinter"]}},"454160ed72e88797129d84ee589de304":{"have":{"class":{"PythonShebangLinter":87}},"need":{"function":{"pht":290},"class":{"ArcanistLinter":115,"ArcanistLintSeverity":614,"Filesystem":854}},"xmap":{"PythonShebangLinter":["ArcanistLinter"]}},"899b8be78da0be470965682eaa31f00a":{"have":{"class":{"ShellCheckLinter":95}},"need":{"function":{"pht":1835,"id":3051},"class":{"ArcanistExternalLinter":120,"ArcanistLintMessage":3058,"ArcanistLintSeverity":1560,"ArcanistLinter":3106}},"xmap":{"ShellCheckLinter":["ArcanistExternalLinter"]}},"09a933fbbf135320585be52750d93831":{"have":{"class":{"StdintLinter":90}},"need":{"function":{"pht":280},"class":{"ArcanistLinter":111,"ArcanistLintSeverity":589,"Filesystem":897}},"xmap":{"StdintLinter":["ArcanistLinter"]}},"25781df78f6eebfb223296b8265e9d19":{"have":{"class":{"TestsLinter":103}},"need":{"function":{"pht":318,"id":2629},"class":{"ArcanistExternalLinter":123,"ArcanistLintMessage":2636,"Filesystem":776,"ArcanistLinter":2684,"ArcanistLintSeverity":2792}},"xmap":{"TestsLinter":["ArcanistExternalLinter"]}},"4c4adcac26dddfa5e350b85a40097755":{"have":{"class":{"BashShebangLinter":82}},"need":{"function":{"pht":281},"class":{"ArcanistLinter":108,"ArcanistLintSeverity":597,"Filesystem":837}},"xmap":{"BashShebangLinter":["ArcanistLinter"]}}}
+{"__symbol_cache_version__":11,"ae5b7d3d6b8cf9598ce4abaf0cd56b21":{"have":{"class":{"ExtendedConfigurationDrivenLintEngine":19}},"need":{"function":{"newv":159,"pht":933},"class":{"ArcanistLintEngine":65,"ArcanistConfigurationDrivenLintEngine":171,"PhutilConsole":866},"class\/interface":{"ILintOnce":634}},"xmap":{"ExtendedConfigurationDrivenLintEngine":["ArcanistLintEngine"]}},"2809b09d2021203b43c57da33d1fe8bf":{"have":{"class":{"AssertWithSideEffectsLinter":210}},"need":{"function":{"pht":439},"class":{"ArcanistLinter":246,"ArcanistLintSeverity":926,"Filesystem":1170}},"xmap":{"AssertWithSideEffectsLinter":["ArcanistLinter"]}},"90a8b110dc475955f15bb81d37268cb5":{"have":{"class":{"AutoPEP8FormatLinter":75}},"need":{"function":{"pht":297,"execx":769,"id":1903},"class":{"ArcanistExternalLinter":104,"ArcanistLintMessage":1910,"Filesystem":1754,"ArcanistLinter":2017,"ArcanistLintSeverity":2095}},"xmap":{"AutoPEP8FormatLinter":["ArcanistExternalLinter"]}},"4c4adcac26dddfa5e350b85a40097755":{"have":{"class":{"BashShebangLinter":82}},"need":{"function":{"pht":281},"class":{"ArcanistLinter":108,"ArcanistLintSeverity":597,"Filesystem":837}},"xmap":{"BashShebangLinter":["ArcanistLinter"]}},"5ea58c19df0397ed8ee0f463d90d6c72":{"have":{"class":{"BoostDependenciesLinter":145}},"need":{"function":{"pht":330,"id":1440},"class":{"GlobalExternalLinter":177,"ArcanistLintMessage":1447,"Filesystem":609,"ArcanistLinter":1524,"ArcanistLintSeverity":1624}},"xmap":{"BoostDependenciesLinter":["GlobalExternalLinter"]}},"38f0c676bff5192a344464142caaa253":{"have":{"class":{"CHeaderLinter":99}},"need":{"function":{"pht":611},"class":{"ArcanistLinter":121,"ArcanistLintSeverity":1060,"Filesystem":1307}},"xmap":{"CHeaderLinter":["ArcanistLinter"]}},"9bb48ec0fe2e9ced8e27d42540d0571c":{"have":{"class":{"CheckDocLinter":106}},"need":{"function":{"pht":321,"id":1845},"class":{"GlobalExternalLinter":129,"ArcanistLintMessage":1852,"Filesystem":729,"ArcanistLinter":1900,"ArcanistLintSeverity":1986}},"xmap":{"CheckDocLinter":["GlobalExternalLinter"]}},"63d19a8745cb2e1200cc26488dc7ad25":{"have":{"class":{"CheckRpcMappingsLinter":131}},"need":{"function":{"pht":310,"id":1386},"class":{"GlobalExternalLinter":162,"ArcanistLintMessage":1393,"Filesystem":573,"ArcanistLinter":1443,"ArcanistLintSeverity":1544}},"xmap":{"CheckRpcMappingsLinter":["GlobalExternalLinter"]}},"1c03a4631b02b8e1ebcc3a078dc1e4af":{"have":{"class":{"ClangFormatLinter":79}},"need":{"function":{"pht":302,"execx":781,"id":2235},"class":{"ArcanistExternalLinter":105,"ArcanistLintMessage":2242,"Filesystem":2086,"ArcanistLinter":2349,"ArcanistLintSeverity":2427}},"xmap":{"ClangFormatLinter":["ArcanistExternalLinter"]}},"75579a609dd975aa0226add52700c622":{"have":{"class":{"FileNameLinter":103}},"need":{"function":{"pht":307},"class":{"ArcanistLinter":126,"ArcanistLintSeverity":662,"Filesystem":968}},"xmap":{"FileNameLinter":["ArcanistLinter"]}},"9285ad9415f8ebe564f7119e5a72c559":{"have":{"class":{"FormatStringLinter":146}},"need":{"function":{"pht":377,"csprintf":1492,"id":1872},"class":{"ArcanistExternalLinter":173,"ArcanistLintMessage":1879,"Filesystem":827,"ArcanistLinter":1956,"ArcanistLintSeverity":2044}},"xmap":{"FormatStringLinter":["ArcanistExternalLinter"]}},"2e11dd9ad67e594f863bc46ac59ea37e":{"have":{"class":{"GlobalExternalLinter":199}},"need":{"class":{"ArcanistExternalLinter":228},"interface":{"ILintOnce":262}},"xmap":{"GlobalExternalLinter":["ArcanistExternalLinter","ILintOnce"]}},"b2403124ec3e8be6cb4d10bf0f6c4134":{"have":{"interface":{"ILintOnce":69}},"need":[],"xmap":[]},"1f9bac7956f4f948a187828dcc6ba2d0":{"have":{"class":{"IncludeGuardLinter":98}},"need":{"function":{"pht":368},"class":{"ArcanistLinter":125,"ArcanistLintSeverity":721,"Filesystem":970}},"xmap":{"IncludeGuardLinter":["ArcanistLinter"]}},"2cbb6e7228d81557f777ad648704f343":{"have":{"class":{"IncludeQuotesLinter":100}},"need":{"function":{"pht":306},"class":{"ArcanistLinter":128,"ArcanistLintSeverity":663,"Filesystem":964}},"xmap":{"IncludeQuotesLinter":["ArcanistLinter"]}},"f151089cf79fdb8257b2272ed4782d88":{"have":{"class":{"IncludeSourceLinter":99}},"need":{"function":{"pht":391},"class":{"ArcanistLinter":127,"ArcanistLintSeverity":699,"Filesystem":938}},"xmap":{"IncludeSourceLinter":["ArcanistLinter"]}},"8a0f2ba683e96feeb9d9564af01fe3e7":{"have":{"class":{"LocaleDependenceLinter":160}},"need":{"function":{"pht":5460},"class":{"ArcanistLinter":191,"ArcanistLintSeverity":5963,"Filesystem":6209}},"xmap":{"LocaleDependenceLinter":["ArcanistLinter"]}},"6f2f22dd0f259fb2eaa284b4fab3bc29":{"have":{"class":{"PythonFormatLinter":123}},"need":{"function":{"pht":353,"id":1838},"class":{"ArcanistExternalLinter":150,"ArcanistLintMessage":1845,"Filesystem":776,"ArcanistLinter":1970,"ArcanistLintSeverity":2053}},"xmap":{"PythonFormatLinter":["ArcanistExternalLinter"]}},"03cf226fe177a9fce7dc046816cc466b":{"have":{"class":{"PythonOpenFileEncodingLinter":111}},"need":{"function":{"pht":325},"class":{"ArcanistLinter":148,"ArcanistLintSeverity":687,"Filesystem":991}},"xmap":{"PythonOpenFileEncodingLinter":["ArcanistLinter"]}},"454160ed72e88797129d84ee589de304":{"have":{"class":{"PythonShebangLinter":87}},"need":{"function":{"pht":290},"class":{"ArcanistLinter":115,"ArcanistLintSeverity":614,"Filesystem":854}},"xmap":{"PythonShebangLinter":["ArcanistLinter"]}},"09a933fbbf135320585be52750d93831":{"have":{"class":{"StdintLinter":90}},"need":{"function":{"pht":280},"class":{"ArcanistLinter":111,"ArcanistLintSeverity":589,"Filesystem":897}},"xmap":{"StdintLinter":["ArcanistLinter"]}},"25781df78f6eebfb223296b8265e9d19":{"have":{"class":{"TestsLinter":103}},"need":{"function":{"pht":318,"id":2629},"class":{"ArcanistExternalLinter":123,"ArcanistLintMessage":2636,"Filesystem":776,"ArcanistLinter":2684,"ArcanistLintSeverity":2792}},"xmap":{"TestsLinter":["ArcanistExternalLinter"]}},"c5bb63c97d3e04f6e0906d001bd3f8a2":{"have":{"class":{"ShellCheckLinter":95}},"need":{"function":{"pht":921,"id":2137},"class":{"ArcanistExternalLinter":120,"ArcanistLintMessage":2144,"ArcanistLintSeverity":646,"ArcanistLinter":2192}},"xmap":{"ShellCheckLinter":["ArcanistExternalLinter"]}}}

arcanist/linter/ShellCheckLinter.php

@@ -7,22 +7,10 @@ final class ShellCheckLinter extends ArcanistExternalLinter {
   const SHELLCHECK_EXCLUDED_RULES = array(
     // phpcs:disable Generic.Files.LineLength.TooLong
     // phpcs:disable Generic.Files.LineLength.MaxExceeded
-    'SC2001', // See if you can use ${variable//search/replace} instead.
-    'SC2004', // $/${} is unnecessary on arithmetic variables.
-    'SC2005', // Useless echo? Instead of 'echo $(cmd)', just use 'cmd'.
-    'SC2006', // Use $(..) instead of legacy `..`.
-    'SC2016', // Expressions don't expand in single quotes, use double quotes for that.
-    'SC2028', // echo won't expand escape sequences. Consider printf.
+    'SC1117', // Backslash is literal in "\.". Prefer explicit escaping: "\\.".
     'SC2046', // Quote this to prevent word splitting.
-    'SC2048', // Use "$@" (with quotes) to prevent whitespace problems.
-    'SC2066', // Since you double quoted this, it will not word split, and the loop will only run once.
     'SC2086', // Double quote to prevent globbing and word splitting.
-    'SC2116', // Useless echo? Instead of 'cmd $(echo foo)', just use 'cmd foo'.
-    'SC2148', // Tips depend on target shell and yours is unknown. Add a shebang.
     'SC2162', // read without -r will mangle backslashes.
-    'SC2166', // Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.
-    'SC2166', // Prefer [ p ] || [ q ] as [ p -o q ] is not well defined.
-    'SC2181', // Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.
     // phpcs:enable
   );
 

autogen.sh

@@ -6,10 +6,10 @@
 set -e
 srcdir="$(dirname $0)"
 cd "$srcdir"
-if [ -z ${LIBTOOLIZE} ] && GLIBTOOLIZE="`which glibtoolize 2>/dev/null`"; then
+if [ -z ${LIBTOOLIZE} ] && GLIBTOOLIZE="$(command -v glibtoolize)"; then
   LIBTOOLIZE="${GLIBTOOLIZE}"
   export LIBTOOLIZE
 fi
-which autoreconf >/dev/null || \
+command -v autoreconf >/dev/null || \
   (echo "configuration failed, please install autoconf first" && exit 1)
 autoreconf --install --force --warnings=all

contrib/devtools/gen-manpages.sh

@@ -14,7 +14,7 @@ BITCOINQT=${BITCOINQT:-$BINDIR/qt/bitcoin-qt}
 [ ! -x $BITCOIND ] && echo "$BITCOIND not found or not executable." && exit 1
 
 # The autodetected version git tag can screw up manpage output a little bit
-BTCVER=($($BITCOINCLI --version | head -n1 | awk -F'[ -]' '{ print $6, $7 }'))
+read -r -a BTCVER <<< "$($BITCOINCLI --version | head -n1 | awk -F'[ -]' '{ print $6, $7 }')"
 
 # Create a footer file with copyright content.
 # This gets autodetected fine for bitcoind if --version-string is not set,

contrib/gitian/provisioner.sh

@@ -62,5 +62,5 @@ echo "As the user ${BUILDUSER} run the following commands to produce a linux bui
 echo "export COMMIT=v0.18.3"
 echo "export URL=https://github.com/Bitcoin-ABC/bitcoin-abc.git"
 echo "cd gitian-builder"
-echo './bin/make-base-vm --lxc --distro debian --suite stretch --arch amd64'
-echo './bin/gbuild --commit bitcoin=${COMMIT} --url bitcoin=${URL} /vagrant/contrib/gitian-descriptors/gitian-linux.yml'
+echo "./bin/make-base-vm --lxc --distro debian --suite stretch --arch amd64"
+echo "./bin/gbuild --commit bitcoin=\${COMMIT} --url bitcoin=\${URL} /vagrant/contrib/gitian-descriptors/gitian-linux.yml"

contrib/macdeploy/detached-sig-apply.sh

@@ -35,13 +35,13 @@ if [ -z "${CODESIGN_ALLOCATE}" ]; then
 fi
 
 find ${TEMPDIR} -name "*.sign" | while read i; do
-  SIZE=`stat -c %s "${i}"`
-  TARGET_FILE="`echo "${i}" | sed 's/\.sign$//'`"
+  SIZE=$(stat -c %s "${i}")
+  TARGET_FILE="$(echo "${i}" | sed 's/\.sign$//')"
 
   echo "Allocating space for the signature of size ${SIZE} in ${TARGET_FILE}"
   ${CODESIGN_ALLOCATE} -i "${TARGET_FILE}" -a ${ARCH} ${SIZE} -o "${i}.tmp"
 
-  OFFSET=`${PAGESTUFF} "${i}.tmp" -p | tail -2 | grep offset | sed 's/[^0-9]*//g'`
+  OFFSET=$(${PAGESTUFF} "${i}.tmp" -p | tail -2 | grep offset | sed 's/[^0-9]*//g')
   if [ -z ${QUIET} ]; then
     echo "Attaching signature at offset ${OFFSET}"
   fi

contrib/macdeploy/detached-sig-create.sh

@@ -13,7 +13,7 @@ TEMPLIST=${TEMPDIR}/signatures.txt
 OUT=signature.tar.gz
 OUTROOT=osx
 
-if [ ! -n "$1" ]; then
+if [ -z "$1" ]; then
   echo "usage: $0 <codesign args>"
   echo "example: $0 -s MyIdentity"
   exit 1
@@ -25,20 +25,20 @@ mkdir -p ${TEMPDIR}
 ${CODESIGN} -f --file-list ${TEMPLIST} "$@" "${BUNDLE}"
 
 grep -v CodeResources < "${TEMPLIST}" | while read i; do
-  TARGETFILE="${BUNDLE}/`echo "${i}" | sed "s|.*${BUNDLE}/||"`"
-  SIZE=`pagestuff "$i" -p | tail -2 | grep size | sed 's/[^0-9]*//g'`
-  OFFSET=`pagestuff "$i" -p | tail -2 | grep offset | sed 's/[^0-9]*//g'`
+  TARGETFILE="${BUNDLE}/$(echo "${i}" | sed "s|.*${BUNDLE}/||")"
+  SIZE=$(pagestuff "$i" -p | tail -2 | grep size | sed 's/[^0-9]*//g')
+  OFFSET=$(pagestuff "$i" -p | tail -2 | grep offset | sed 's/[^0-9]*//g')
   SIGNFILE="${TEMPDIR}/${OUTROOT}/${TARGETFILE}.sign"
-  DIRNAME="`dirname "${SIGNFILE}"`"
+  DIRNAME="$(dirname "${SIGNFILE}")"
   mkdir -p "${DIRNAME}"
   echo "Adding detached signature for: ${TARGETFILE}. Size: ${SIZE}. Offset: ${OFFSET}"
   dd if="$i" of="${SIGNFILE}" bs=1 skip=${OFFSET} count=${SIZE} 2>/dev/null
 done
 
 grep CodeResources < "${TEMPLIST}" | while read i; do
-  TARGETFILE="${BUNDLE}/`echo "${i}" | sed "s|.*${BUNDLE}/||"`"
+  TARGETFILE="${BUNDLE}/$(echo "${i}" | sed "s|.*${BUNDLE}/||")"
   RESOURCE="${TEMPDIR}/${OUTROOT}/${TARGETFILE}"
-  DIRNAME="`dirname "${RESOURCE}"`"
+  DIRNAME="$(dirname "${RESOURCE}")"
   mkdir -p "${DIRNAME}"
   echo "Adding resource for: \"${TARGETFILE}\""
   cp "${i}" "${RESOURCE}"

contrib/qos/tc.sh

@@ -32,7 +32,7 @@ tc class add dev ${IF} parent 1:1 classid 1:11 htb rate ${LIMIT} ceil ${LIMIT} p
 tc filter add dev ${IF} parent 1: protocol ip prio 1 handle 1 fw classid 1:10
 tc filter add dev ${IF} parent 1: protocol ip prio 2 handle 2 fw classid 1:11
 
-if [ ! -z "${LOCALNET_V6}" ] ; then
+if [ -n "${LOCALNET_V6}" ] ; then
 	# v6 cannot have the same priority value as v4
 	tc filter add dev ${IF} parent 1: protocol ipv6 prio 3 handle 1 fw classid 1:10
 	tc filter add dev ${IF} parent 1: protocol ipv6 prio 4 handle 2 fw classid 1:11
@@ -55,7 +55,7 @@ fi
 iptables -t mangle -A OUTPUT -p tcp -m tcp --dport 8333 ! -d ${LOCALNET_V4} -j MARK --set-mark 0x2
 iptables -t mangle -A OUTPUT -p tcp -m tcp --sport 8333 ! -d ${LOCALNET_V4} -j MARK --set-mark 0x2
 
-if [ ! -z "${LOCALNET_V6}" ] ; then
+if [ -n "${LOCALNET_V6}" ] ; then
 	ip6tables -t mangle -A OUTPUT -p tcp -m tcp --dport 8333 ! -d ${LOCALNET_V6} -j MARK --set-mark 0x4
 	ip6tables -t mangle -A OUTPUT -p tcp -m tcp --sport 8333 ! -d ${LOCALNET_V6} -j MARK --set-mark 0x4
 fi

contrib/teamcity/build-configurations.sh

@@ -9,7 +9,7 @@ fi
 
 echo "Running build configuration '${ABC_BUILD_NAME}'..."
 
-TOPLEVEL=`git rev-parse --show-toplevel`
+TOPLEVEL=$(git rev-parse --show-toplevel)
 cd "${TOPLEVEL}/contrib/teamcity"
 
 case "$ABC_BUILD_NAME" in

contrib/teamcity/build-secp256k1.sh

@@ -2,10 +2,10 @@
 
 set -eu
 
-TOPLEVEL=`git rev-parse --show-toplevel`
+TOPLEVEL=$(git rev-parse --show-toplevel)
 if [[ -z "${TOPLEVEL}" ]]; then
 	echo "No .git directory found, assuming pwd"
-	TOPLEVEL=`pwd -P`
+	TOPLEVEL=$(pwd -P)
 fi
 SECP_DIR="${TOPLEVEL}/src/secp256k1"
 
@@ -28,4 +28,3 @@ make -j ${THREADS}
 
 # Run Java tests
 make check-java
-