diff --git a/arcanist/.phutil_module_cache b/arcanist/.phutil_module_cache
index ef8052d8c..40f7e319a 100644
--- a/arcanist/.phutil_module_cache
+++ b/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":{"ArcanistL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\ No newline at end of file
+{"__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"]}}}
\ No newline at end of file
diff --git a/arcanist/linter/ShellCheckLinter.php b/arcanist/linter/ShellCheckLinter.php
index 5edc7b9ea..8f34d735d 100644
--- a/arcanist/linter/ShellCheckLinter.php
+++ b/arcanist/linter/ShellCheckLinter.php
@@ -1,99 +1,87 @@
 <?php
 
 /**
  * Uses the ShellCheck tool to run static analysis on shell scripts
  */
 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
   );
 
   const SHELLCHECK_SEVERITY_MAP = array(
       'note' => ArcanistLintSeverity::SEVERITY_ADVICE,
       'warning' => ArcanistLintSeverity::SEVERITY_WARNING,
       'error' => ArcanistLintSeverity::SEVERITY_ERROR,
   );
 
   public function getInfoName() {
     return 'shellcheck';
   }
 
   public function getInfoDescription() {
     return pht('Use shellcheck for processing specified files.');
   }
 
   public function getLinterName() {
     return 'SHELLCHECK';
   }
 
   public function getLinterConfigurationName() {
     return 'shellcheck';
   }
 
   public function getDefaultBinary() {
     return 'shellcheck';
   }
 
   public function getInstallInstructions() {
     return pht('Make sure shellcheck is in directory specified by $PATH');
   }
 
   public function shouldExpectCommandErrors() {
     return true;
   }
 
   protected function getMandatoryFlags() {
     return array(
       '--format=gcc',
       '--exclude='.implode(',', self::SHELLCHECK_EXCLUDED_RULES));
   }
 
   private function getSeverity($severity) {
     if (array_key_exists($severity, self::SHELLCHECK_SEVERITY_MAP)) {
       return self::SHELLCHECK_SEVERITY_MAP[$severity];
     }
 
     return ArcanistLintSeverity::SEVERITY_ERROR;
   }
 
   protected function parseLinterOutput($path, $err, $stdout, $stderr) {
     $messages = array();
 
     $pattern = '/(.+):(\d+):(\d+): (.+): (.+) \[(SC\d+)\]/';
     if (preg_match_all($pattern, $stdout, $errors, PREG_SET_ORDER)) {
       foreach ($errors as $error) {
         list(, $file, $line, $char, $severity, $message, $code) = $error;
 
         $messages[] = id(new ArcanistLintMessage())
         ->setGranularity(ArcanistLinter::GRANULARITY_FILE)
         ->setPath($path)
         ->setLine($line)
         ->setChar($char)
         ->setCode($code)
         ->setSeverity($this->getSeverity($severity))
         ->setName('ShellCheck found an issue:')
         ->setDescription($message);
       }
     }
 
     return $messages;
   }
 }
diff --git a/autogen.sh b/autogen.sh
index 27417daf7..f567e4232 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,15 +1,15 @@
 #!/bin/sh
 # Copyright (c) 2013-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 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
diff --git a/contrib/devtools/gen-manpages.sh b/contrib/devtools/gen-manpages.sh
index 8d1a89356..03c065a7b 100755
--- a/contrib/devtools/gen-manpages.sh
+++ b/contrib/devtools/gen-manpages.sh
@@ -1,31 +1,31 @@
 #!/usr/bin/env bash
 
 TOPDIR=${TOPDIR:-$(git rev-parse --show-toplevel)}
 BUILDDIR=${BUILDDIR:-$TOPDIR}
 
 BINDIR=${BINDIR:-$BUILDDIR/src}
 MANDIR=${MANDIR:-$TOPDIR/doc/man}
 
 BITCOIND=${BITCOIND:-$BINDIR/bitcoind}
 BITCOINCLI=${BITCOINCLI:-$BINDIR/bitcoin-cli}
 BITCOINTX=${BITCOINTX:-$BINDIR/bitcoin-tx}
 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,
 # but has different outcomes for bitcoin-qt and bitcoin-cli.
 echo "[COPYRIGHT]" > footer.h2m
 $BITCOIND --version | sed -n '1!p' >> footer.h2m
 
 for cmd in $BITCOIND $BITCOINCLI $BITCOINTX $BITCOINQT; do
   cmdname="${cmd##*/}"
   help2man -N --version-string=${BTCVER[0]} --include=footer.h2m -o ${MANDIR}/${cmdname}.1 ${cmd}
   sed -i "s/\\\-${BTCVER[1]}//g" ${MANDIR}/${cmdname}.1
 done
 
 rm -f footer.h2m
diff --git a/contrib/gitian/provisioner.sh b/contrib/gitian/provisioner.sh
index eebc3f82e..9e2e026b7 100644
--- a/contrib/gitian/provisioner.sh
+++ b/contrib/gitian/provisioner.sh
@@ -1,66 +1,66 @@
 #!/usr/bin/env bash
 
 set -e
 
 # User to setup for building.  Vagrant is the default
 export BUILDUSER=${BUILDUSER:-vagrant}
 
 apt-get update
 apt-get install -y git ruby sudo apt-cacher-ng qemu-utils debootstrap \
 	lxc python-cheetah parted kpartx bridge-utils make curl 
 
 # the version of lxc-start in Debian needs to run as root, so make sure
 # that the build script can execute it without providing a password
 echo "%sudo ALL=NOPASSWD: /usr/bin/lxc-start" > /etc/sudoers.d/gitian-lxc
 echo "%sudo ALL=NOPASSWD: /usr/bin/lxc-execute" >> /etc/sudoers.d/gitian-lxc
 
 # make sure that USE_LXC is always set when logging in as vagrant,
 # and configure LXC IP addresses
 {
 	echo 'export USE_LXC=1'
 	echo 'export LXC_BRIDGE=lxcbr0'
 	echo 'export GITIAN_HOST_IP=10.0.3.1'
 	echo 'export LXC_GUEST_IP=10.0.3.5'
 } >> /home/${BUILDUSER}/.profile
 
 # Setup bridge
 echo 'USE_LXC_BRIDGE="true"' > /etc/default/lxc-net
 {
 	echo 'lxc.network.type = veth'
 	echo 'lxc.network.link = lxcbr0'
 	echo 'lxc.network.flags = up'
 	echo 'lxc.network.hwaddr = 00:16:3e:xx:xx:xx'
 } > /etc/lxc/default.conf
 service lxc-net restart
 
 # chdir into build user home directory
 cd /home/${BUILDUSER}/
 
 ## Install vm-builder
 wget http://archive.ubuntu.com/ubuntu/pool/universe/v/vm-builder/vm-builder_0.12.4+bzr494.orig.tar.gz
 echo "76cbf8c52c391160b2641e7120dbade5afded713afaa6032f733a261f13e6a8e  vm-builder_0.12.4+bzr494.orig.tar.gz" | sha256sum -c
 # (verification -- must return OK)
 tar -zxvf vm-builder_0.12.4+bzr494.orig.tar.gz
 cd vm-builder-0.12.4+bzr494
 sudo python setup.py install
 cd ..
 
 ## Install Gitian
 git clone https://github.com/devrandom/gitian-builder.git
 cd gitian-builder
 
 git config --global user.email "vagrant@vagrant.com"
 git config --global user.name "vagrant"
 
 chown -R ${BUILDUSER}:${BUILDUSER} /home/${BUILDUSER}  
 
 echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
 echo "!!! Provisioning Complete !!!!"
 echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
 echo 
 echo "As the user ${BUILDUSER} run the following commands to produce a linux build:"
 echo "export COMMIT=v0.18.3"
 echo "export URL=https://github.com/Bitcoin-ABC/bitcoin-abc.git"
 echo "cd gitian-builder"
-echo './bin/make-base-vm --lxc --distro debian --suite stretch --arch amd64'
-echo './bin/gbuild --commit bitcoin=${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"
diff --git a/contrib/macdeploy/detached-sig-apply.sh b/contrib/macdeploy/detached-sig-apply.sh
index 91674a92e..7fe15e793 100755
--- a/contrib/macdeploy/detached-sig-apply.sh
+++ b/contrib/macdeploy/detached-sig-apply.sh
@@ -1,56 +1,56 @@
 #!/bin/sh
 # Copyright (c) 2014-2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 set -e
 
 UNSIGNED="$1"
 SIGNATURE="$2"
 ARCH=x86_64
 ROOTDIR=dist
 TEMPDIR=signed.temp
 OUTDIR=signed-app
 
 if [ -z "$UNSIGNED" ]; then
   echo "usage: $0 <unsigned app> <signature>"
   exit 1
 fi
 
 if [ -z "$SIGNATURE" ]; then
   echo "usage: $0 <unsigned app> <signature>"
   exit 1
 fi
 
 rm -rf ${TEMPDIR} && mkdir -p ${TEMPDIR}
 tar -C ${TEMPDIR} -xf ${UNSIGNED}
 cp -rf "${SIGNATURE}"/* ${TEMPDIR}
 
 if [ -z "${PAGESTUFF}" ]; then
   PAGESTUFF=${TEMPDIR}/pagestuff
 fi
 
 if [ -z "${CODESIGN_ALLOCATE}" ]; then
   CODESIGN_ALLOCATE=${TEMPDIR}/codesign_allocate
 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
 
   dd if="$i" of="${i}.tmp" bs=1 seek=${OFFSET} count=${SIZE} 2>/dev/null
   mv "${i}.tmp" "${TARGET_FILE}"
   rm "${i}"
   echo "Success."
 done
 mv ${TEMPDIR}/${ROOTDIR} ${OUTDIR}
 rm -rf ${TEMPDIR}
 echo "Signed: ${OUTDIR}"
diff --git a/contrib/macdeploy/detached-sig-create.sh b/contrib/macdeploy/detached-sig-create.sh
index 9cb343845..efa4d14bc 100755
--- a/contrib/macdeploy/detached-sig-create.sh
+++ b/contrib/macdeploy/detached-sig-create.sh
@@ -1,51 +1,51 @@
 #!/bin/sh
 # Copyright (c) 2014-2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 set -e
 
 ROOTDIR=dist
 BUNDLE="${ROOTDIR}/BitcoinABC-Qt.app"
 CODESIGN=codesign
 TEMPDIR=sign.temp
 TEMPLIST=${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
 fi
 
 rm -rf ${TEMPDIR} ${TEMPLIST}
 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}"
 done
 
 rm ${TEMPLIST}
 
 tar -C "${TEMPDIR}" -czf "${OUT}" .
 rm -rf "${TEMPDIR}"
 echo "Created ${OUT}"
diff --git a/contrib/qos/tc.sh b/contrib/qos/tc.sh
index f3e64ca82..3a346d99a 100644
--- a/contrib/qos/tc.sh
+++ b/contrib/qos/tc.sh
@@ -1,61 +1,61 @@
 #!/usr/bin/env bash
 #
 # Copyright (c) 2017 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #network interface on which to limit traffic
 IF="eth0"
 #limit of the network interface in question
 LINKCEIL="1gbit"
 #limit outbound Bitcoin protocol traffic to this rate
 LIMIT="160kbit"
 #defines the IPv4 address space for which you wish to disable rate limiting
 LOCALNET_V4="192.168.0.0/16"
 #defines the IPv6 address space for which you wish to disable rate limiting
 LOCALNET_V6="fe80::/10"
 
 #delete existing rules
 tc qdisc del dev ${IF} root
 
 #add root class
 tc qdisc add dev ${IF} root handle 1: htb default 10
 
 #add parent class
 tc class add dev ${IF} parent 1: classid 1:1 htb rate ${LINKCEIL} ceil ${LINKCEIL}
 
 #add our two classes. one unlimited, another limited
 tc class add dev ${IF} parent 1:1 classid 1:10 htb rate ${LINKCEIL} ceil ${LINKCEIL} prio 0
 tc class add dev ${IF} parent 1:1 classid 1:11 htb rate ${LIMIT} ceil ${LIMIT} prio 1
 
 #add handles to our classes so packets marked with <x> go into the class with "... handle <x> fw ..."
 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
 fi
 
 #delete any existing rules
 #disable for now
 #ret=0
 #while [ $ret -eq 0 ]; do
 #	iptables -t mangle -D OUTPUT 1
 #	ret=$?
 #done
 
 #limit outgoing traffic to and from port 8333. but not when dealing with a host on the local network
 #	(defined by $LOCALNET_V4 and $LOCALNET_V6)
 #	--set-mark marks packages matching these criteria with the number "2" (v4)
 #	--set-mark marks packages matching these criteria with the number "4" (v6)
 #	these packets are filtered by the tc filter with "handle 2"
 #	this filter sends the packages into the 1:11 class, and this class is limited to ${LIMIT}
 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
diff --git a/contrib/teamcity/build-configurations.sh b/contrib/teamcity/build-configurations.sh
index 5b4a1a43f..4a5f0d85e 100755
--- a/contrib/teamcity/build-configurations.sh
+++ b/contrib/teamcity/build-configurations.sh
@@ -1,40 +1,40 @@
 #!/usr/bin/env bash
 
 set -e
 
 if [ -z "$ABC_BUILD_NAME" ]; then
   echo "Error: Environment variable ABC_BUILD_NAME must be set"
   exit 1
 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
   build-asan)
     export CONFIGURE_FLAGS="--enable-debug --with-sanitizers=address --disable-ccache"
     ./build.sh
     ;;
 
   build-ubsan)
     export CONFIGURE_FLAGS="--enable-debug --with-sanitizers=undefined --disable-ccache CC=clang CXX=clang++"
     ./build.sh
     ;;
 
   build-default)
     ./build.sh
     ./build-secp256k1.sh
     ;;
 
   build-without-wallet)
     export DISABLE_WALLET=1
     ./build.sh
     ;;
 
   *)
     echo "Error: Invalid build name '${ABC_BUILD_NAME}'"
     exit 2
     ;;
 esac
diff --git a/contrib/teamcity/build-secp256k1.sh b/contrib/teamcity/build-secp256k1.sh
index df2c4f954..228c832ee 100755
--- a/contrib/teamcity/build-secp256k1.sh
+++ b/contrib/teamcity/build-secp256k1.sh
@@ -1,31 +1,30 @@
 #!/usr/bin/env bash
 
 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"
 
 # Generate necessary autoconf files
 cd ${SECP_DIR}
 ./autogen.sh
 
 # Setup build directory
 BUILD_DIR="${SECP_DIR}/build"
 mkdir -p ${BUILD_DIR}
 cd ${BUILD_DIR}
 
 # Determine the number of build threads
 THREADS=$(nproc || sysctl -n hw.ncpu)
 
 ../configure --enable-jni --enable-experimental --enable-module-ecdh
 
 # Run build
 make -j ${THREADS}
 
 # Run Java tests
 make check-java
-
diff --git a/contrib/teamcity/build.sh b/contrib/teamcity/build.sh
index f29ad2970..af84d86e5 100755
--- a/contrib/teamcity/build.sh
+++ b/contrib/teamcity/build.sh
@@ -1,88 +1,88 @@
 #!/usr/bin/env bash
 
 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
 
 BUILD_DIR="${TOPLEVEL}/build"
 mkdir -p ${BUILD_DIR}
 
 ## Generate necessary autoconf files
 cd ${TOPLEVEL}
 ./autogen.sh
 cd ${BUILD_DIR}
 
 rm -f build.status test_bitcoin.xml
 
 ## Determine the number of build threads
 THREADS=$(nproc || sysctl -n hw.ncpu)
 
 # Default to nothing
-: ${DISABLE_WALLET:=}
-: ${CONFIGURE_FLAGS:=}
+: "${DISABLE_WALLET:=}"
+: "${CONFIGURE_FLAGS:=}"
 
-CONFIGURE_FLAGS=($CONFIGURE_FLAGS "--prefix=`pwd`")
-if [[ ! -z "${DISABLE_WALLET}" ]]; then
+CONFIGURE_FLAGS=("$CONFIGURE_FLAGS" "--prefix=$(pwd)")
+if [[ -n "${DISABLE_WALLET}" ]]; then
 	echo "*** Building without wallet"
 	CONFIGURE_FLAGS+=("--disable-wallet")
 fi
 
 ../configure "${CONFIGURE_FLAGS[@]}"
 
 # Base directories for sanitizer related files 
 SAN_SUPP_DIR="${TOPLEVEL}/test/sanitizer_suppressions"
 SAN_LOG_DIR="${BUILD_DIR}/sanitizer_logs"
 
 # Create the log directory if it doesn't exist and clear it
 mkdir -p "${SAN_LOG_DIR}"
 rm -rf "${SAN_LOG_DIR:?}"/*
 
 # Sanitizers options, not used if sanitizers are not enabled
 export ASAN_OPTIONS="malloc_context_size=0:log_path=${SAN_LOG_DIR}/asan.log"
 export LSAN_OPTIONS="suppressions=${SAN_SUPP_DIR}/lsan:log_path=${SAN_LOG_DIR}/lsan.log"
 export TSAN_OPTIONS="suppressions=${SAN_SUPP_DIR}/tsan:log_path=${SAN_LOG_DIR}/tsan.log"
 export UBSAN_OPTIONS="suppressions=${SAN_SUPP_DIR}/ubsan:print_stacktrace=1:halt_on_error=1:log_path=${SAN_LOG_DIR}/ubsan.log"
 
 function print_sanitizers_log() {
 	for log in "${SAN_LOG_DIR}"/*.log.*
 	do
 		echo "*** Output of ${log} ***"
 		cat "${log}"
 	done
 }
 
 # Run build
 make -j ${THREADS}
 
 # Default to nothing
-: ${DISABLE_TESTS:=}
+: "${DISABLE_TESTS:=}"
 
 # If DISABLE_TESTS is unset (default), run the tests
 if [[ -z "${DISABLE_TESTS}" ]]; then
 	echo "*** Running tests"
 
 	# Run unit tests
 	make -j ${THREADS} check || (print_sanitizers_log && exit 1)
 
 	mkdir -p output/
 	BRANCH=$(git rev-parse --abbrev-ref HEAD)
 	JUNIT_DEFAULT="junit_results_default.xml"
 	JUNIT_NEXT_UPGRADE="junit_results_next_upgrade.xml"
 
-	if [[ ! -z "${DISABLE_WALLET}" ]]; then
+	if [[ -n "${DISABLE_WALLET}" ]]; then
 		echo "Skipping rpc testing due to disabled wallet functionality."
 	elif [[ "${BRANCH}" == "master" ]]; then
 		./test/functional/test_runner.py -J="${JUNIT_DEFAULT}" --cutoff=600 --tmpdirprefix=output
 		./test/functional/test_runner.py -J="${JUNIT_NEXT_UPGRADE}" --cutoff=600 --tmpdirprefix=output --with-gravitonactivation
 	else
 		./test/functional/test_runner.py -J="${JUNIT_DEFAULT}" --tmpdirprefix=output
 		./test/functional/test_runner.py -J="${JUNIT_NEXT_UPGRADE}" --tmpdirprefix=output --with-gravitonactivation
 	fi
 else
 	echo "*** Tests have been skipped"
 fi
 
diff --git a/contrib/teamcity/gitian.sh b/contrib/teamcity/gitian.sh
index e478aaee1..b3a0f4372 100755
--- a/contrib/teamcity/gitian.sh
+++ b/contrib/teamcity/gitian.sh
@@ -1,35 +1,35 @@
 #!/usr/bin/env bash
 
 set -e
 
 cd "$(dirname "$0")"
 
-COMMIT=`git rev-parse HEAD`
+COMMIT=$(git rev-parse HEAD)
 export COMMIT
-PROJECT_ROOT=`git rev-parse --show-toplevel`
+PROJECT_ROOT=$(git rev-parse --show-toplevel)
 export PROJECT_ROOT
 export USE_LXC=1
 export GITIAN_HOST_IP=10.0.3.1
 export LXC_BRIDGE=lxcbr0
 export LXC_GUEST_IP=10.0.3.5
 
 cd ~/gitian-builder
 
 if [[ "${OS_NAME}" == "osx" ]]; then
   wget https://storage.googleapis.com/f4936e83b2dcbca742be51fb9692b153/MacOSX10.11.sdk.tar.gz
   echo "4732b52b5ebe300c8c91cbeed6d19d59c1ff9c56c7a1dd6cfa518b9c2c72abde  MacOSX10.11.sdk.tar.gz" | sha256sum -c
   mkdir -p inputs
   echo "Downloaded"
   mv MacOSX10.11.sdk.tar.gz inputs
 fi
 
 ## Determine the number of build threads
 THREADS=$(nproc || sysctl -n hw.ncpu)
 
 ./bin/gbuild -j${THREADS} -m3500 --commit bitcoin=${COMMIT} --url bitcoin="${PROJECT_ROOT}" "${PROJECT_ROOT}/contrib/gitian-descriptors/gitian-${OS_NAME}.yml"
 
 RESULT_DIR="${PROJECT_ROOT}/gitian-results/${OS_NAME}"
 mkdir -p "${RESULT_DIR}"
 mv var/build.log "${PROJECT_ROOT}/gitian-results/"
 mv result/*.yml "${RESULT_DIR}/"    
 mv build/out/* "${RESULT_DIR}/"
diff --git a/contrib/teamcity/ibd.sh b/contrib/teamcity/ibd.sh
index ddf031784..ad933b23c 100755
--- a/contrib/teamcity/ibd.sh
+++ b/contrib/teamcity/ibd.sh
@@ -1,74 +1,74 @@
 #!/usr/bin/env bash
 
 set -euo pipefail
 
 ###
 # Initial Block Download script.
 #
 # Runs a bitcoind process until initial block download is complete.
 # Forwards the exit code from bitcoind onward.
 ###
 
 MYPID=$$
 
 # Setup
 DATA_DIR="ibd"
 mkdir -p "${DATA_DIR}"
 DEBUG_LOG="${DATA_DIR}/debug.log"
 touch "${DEBUG_LOG}"
 chmod +x bitcoind
 
 # Launch bitcoind using this script's parameters
-./bitcoind "-datadir=${DATA_DIR}" $* &
+./bitcoind "-datadir=${DATA_DIR}" "$@" &
 BITCOIND_PID=$!
 
 cleanup() {
   # Cleanup background processes spawned by this script.
   pkill -P ${MYPID} tail || true
 }
 trap "cleanup" EXIT
 
 # Show some progress
 tail -f "${DEBUG_LOG}" | grep 'UpdateTip' | awk 'NR % 10000 == 0' &
 
 # Wait for IBD to finish and kill the daemon
 (
   (
     # Ignore the broken pipe when tail tries to write pipe closed by grep
     set +o pipefail
     tail -f "${DEBUG_LOG}" | grep -m 1 'progress=1.000000'
   )
   echo "Initial block download complete."
 
   # TODO Add more checks to see if IBD completed as expected,
   # These checks will exit the subshell with a non-zero exit code.
 ) &
 IBD_PID=$!
 
 # When the IBD subshell finishes, kill bitcoind
 (
   while [ -e /proc/${IBD_PID} ]; do sleep 0.1; done
 
   echo "Cleaning up bitcoin daemon (PID: ${BITCOIND_PID})."
   kill ${BITCOIND_PID}
 ) &
 
 # Wait for bitcoind to exit, whether it exited on its own or IBD finished
 wait ${BITCOIND_PID}
 BITCOIND_EXIT_CODE=$?
 
 if [ "${BITCOIND_EXIT_CODE}" -ne "0" ]; then
   echo "bitcoind exited unexpectedly with code: ${BITCOIND_EXIT_CODE}"
   exit ${BITCOIND_EXIT_CODE}
 fi
 
 # Get the exit code for the IBD subshell, which should have exited already
 wait ${IBD_PID}
 IBD_EXIT_CODE=$?
 
 # The IBD subshell should only exit with a non-zero code if one of the tests
 # failed.
 if [ "${IBD_EXIT_CODE}" -ne "0" ]; then
   echo "IBD tests failed with code: ${IBD_EXIT_CODE}"
   exit ${IBD_EXIT_CODE}
 fi
diff --git a/contrib/verifybinaries/verify.sh b/contrib/verifybinaries/verify.sh
index 95f714d34..8071eb87e 100755
--- a/contrib/verifybinaries/verify.sh
+++ b/contrib/verifybinaries/verify.sh
@@ -1,125 +1,124 @@
 #!/usr/bin/env bash
 # Copyright (c) 2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 ###   This script attempts to download the signature file SHA256SUMS.asc from bitcoin.org
 ###   It first checks if the signature passes, and then downloads the files specified in
 ###   the file, and checks if the hashes of these files match those that are specified
 ###   in the signature file.
 ###   The script returns 0 if everything passes the checks. It returns 1 if either the
 ###   signature check or the hash check doesn't pass. If an error occurs the return value is 2
 
 function clean_up {
-   for file in $*
+   for file in "$@"
    do
       rm "$file" 2> /dev/null
    done
 }
 
 WORKINGDIR="/tmp/bitcoin_verify_binaries"
 TMPFILE="hashes.tmp"
 
 SIGNATUREFILENAME="SHA256SUMS.asc"
 RCSUBDIR="test"
 BASEDIR="https://bitcoin.org/bin/"
 VERSIONPREFIX="bitcoin-core-"
 RCVERSIONSTRING="rc"
 
 if [ ! -d "$WORKINGDIR" ]; then
    mkdir "$WORKINGDIR"
 fi
 
 cd "$WORKINGDIR" || exit 1
 
 #test if a version number has been passed as an argument
 if [ -n "$1" ]; then
    #let's also check if the version number includes the prefix 'bitcoin-',
    #  and add this prefix if it doesn't
    if [[ $1 == "$VERSIONPREFIX"* ]]; then
       VERSION="$1"
    else
       VERSION="$VERSIONPREFIX$1"
    fi
 
    #now let's see if the version string contains "rc", and strip it off if it does
    #  and simultaneously add RCSUBDIR to BASEDIR, where we will look for SIGNATUREFILENAME
    if [[ $VERSION == *"$RCVERSIONSTRING"* ]]; then
       BASEDIR="$BASEDIR${VERSION/%-$RCVERSIONSTRING*}/"
       BASEDIR="$BASEDIR$RCSUBDIR.$RCVERSIONSTRING${VERSION: -1}/"
    else
       BASEDIR="$BASEDIR$VERSION/"
    fi
 else
    echo "Error: need to specify a version on the command line"
    exit 2
 fi
 
-#first we fetch the file containing the signature
-WGETOUT=$(wget -N "$BASEDIR$SIGNATUREFILENAME" 2>&1)
-
-#and then see if wget completed successfully
-if [ $? -ne 0 ]; then
+if ! WGETOUT=$(wget -N "$HOST1$BASEDIR$SIGNATUREFILENAME" 2>&1); then
    echo "Error: couldn't fetch signature file. Have you specified the version number in the following format?"
+   # shellcheck disable=SC1087
    echo "[$VERSIONPREFIX]<version>-[$RCVERSIONSTRING[0-9]] (example: ${VERSIONPREFIX}0.10.4-${RCVERSIONSTRING}1)"
    echo "wget output:"
+   # shellcheck disable=SC2001
    echo "$WGETOUT"|sed 's/^/\t/g'
    exit 2
 fi
 
 #then we check it
 GPGOUT=$(gpg --yes --decrypt --output "$TMPFILE" "$SIGNATUREFILENAME" 2>&1)
 
 #return value 0: good signature
 #return value 1: bad signature
 #return value 2: gpg error
 
 RET="$?"
 if [ $RET -ne 0 ]; then
    if [ $RET -eq 1 ]; then
       #and notify the user if it's bad
       echo "Bad signature."
    elif [ $RET -eq 2 ]; then
       #or if a gpg error has occurred
       echo "gpg error. Do you have the Bitcoin Core binary release signing key installed?"
    fi
 
    echo "gpg output:"
+   # shellcheck disable=SC2001
    echo "$GPGOUT"|sed 's/^/\t/g'
    clean_up $SIGNATUREFILENAME $TMPFILE
    exit "$RET"
 fi
 
 #here we extract the filenames from the signature file
 FILES=$(awk '{print $2}' "$TMPFILE")
 
 #and download these one by one
 for file in $FILES
 do
    wget --quiet -N "$BASEDIR$file"
 done
 
 #check hashes
 DIFF=$(diff <(sha256sum $FILES) "$TMPFILE")
 
 if [ $? -eq 1 ]; then
    echo "Hashes don't match."
    echo "Offending files:"
    echo "$DIFF"|grep "^<"|awk '{print "\t"$3}'
    exit 1
 elif [ $? -gt 1 ]; then
    echo "Error executing 'diff'"
    exit 2
 fi
 
 if [ -n "$2" ]; then
    echo "Clean up the binaries"
    clean_up $FILES $SIGNATUREFILENAME $TMPFILE
 else
    echo "Keep the binaries in $WORKINGDIR"
    clean_up $TMPFILE
 fi
 
 echo -e "Verified hashes of \n$FILES"
 
 exit 0
diff --git a/share/genbuild.sh b/share/genbuild.sh
index c8a798e02..b21a734d4 100755
--- a/share/genbuild.sh
+++ b/share/genbuild.sh
@@ -1,48 +1,48 @@
 #!/bin/sh
 # Copyright (c) 2012-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 if [ $# -gt 1 ]; then
     cd "$2" || exit 1
 fi
 if [ $# -gt 0 ]; then
     FILE="$1"
     shift
     if [ -f "$FILE" ]; then
         INFO="$(head -n 1 "$FILE")"
     fi
 else
     echo "Usage: $0 <filename> <srcroot>"
     exit 1
 fi
 
 DESC=""
 SUFFIX=""
-if [ -e "$(which git 2>/dev/null)" -a "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]; then
+if [ -e "$(command -v git)" ] && [ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]; then
     # clean 'dirty' status of touched files that haven't been modified
-    git diff >/dev/null 2>/dev/null 
+    git diff >/dev/null 2>/dev/null
 
     # if latest commit is tagged and not dirty, then override using the tag name
     RAWDESC=$(git describe --abbrev=0 2>/dev/null)
     if [ "$(git rev-parse HEAD)" = "$(git rev-list -1 $RAWDESC 2>/dev/null)" ]; then
         git diff-index --quiet HEAD -- && DESC=$RAWDESC
     fi
 
     # otherwise generate suffix from git, i.e. string like "59887e8-dirty"
     SUFFIX=$(git rev-parse --short HEAD)
     git diff-index --quiet HEAD -- || SUFFIX="$SUFFIX-dirty"
 fi
 
 if [ -n "$DESC" ]; then
     NEWINFO="#define BUILD_DESC \"$DESC\""
 elif [ -n "$SUFFIX" ]; then
     NEWINFO="#define BUILD_SUFFIX $SUFFIX"
 else
     NEWINFO="// No build information available"
 fi
 
 # only update build.h if necessary
 if [ "$INFO" != "$NEWINFO" ]; then
     echo "$NEWINFO" >"$FILE"
 fi
diff --git a/src/qt/res/movies/makespinner.sh b/src/qt/res/movies/makespinner.sh
index d0413efbb..8bc2e8c6a 100755
--- a/src/qt/res/movies/makespinner.sh
+++ b/src/qt/res/movies/makespinner.sh
@@ -1,13 +1,13 @@
 #!/usr/bin/env bash
 
 # Copyright (c) 2014-2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 FRAMEDIR=$(dirname $0)
 for i in {0..35}
 do
     frame=$(printf "%03d" $i)
-    angle=$(($i * 10))
+    angle=$((i * 10))
     convert $FRAMEDIR/../src/spinner.png -background "rgba(0,0,0,0.0)" -distort SRT $angle $FRAMEDIR/spinner-$frame.png
 done
diff --git a/test/functional/test_framework/tests/run_self_tests.sh b/test/functional/test_framework/tests/run_self_tests.sh
index a98559462..0e8c21b7a 100644
--- a/test/functional/test_framework/tests/run_self_tests.sh
+++ b/test/functional/test_framework/tests/run_self_tests.sh
@@ -1,53 +1,53 @@
 #!/bin/sh
 # Copyright (c) 2017 The Bitcoin developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #
 # Executes the test framework self-tests located in
 # qa/rpc-tests/test_framework/tests.
 #
 # You should be able to call this script from pretty much anywhere.
 # It takes care of setting up the PYTHONPATH so tests can run.
 
 # Enable exit on any error.
 set -e
 
 # Save folder from which script was called.
 # We may need to return after looking for the base folder.
 start_folder="$(pwd)"
 
 if [ -d qa/rpc-tests ]
 then
     # called from top level
     RPC_TESTS_DIR=$(pwd)/qa/rpc-tests
 elif [ -d ../qa/rpc-tests ]
 then
     # called from out of tree build
     RPC_TESTS_DIR=$(cd ../qa/rpc-tests && pwd)
 else
     # chop off the script's filename to get path
     scriptpath=$(dirname $0)
     RPC_TESTS_DIR=$(cd $scriptpath/../.. && pwd)
 fi
 
 export PYTHONPATH="$PYTHONPATH:$RPC_TESTS_DIR"
 
 # Go to where the tests are located
 cd $RPC_TESTS_DIR/test_framework/tests
 
 echo "Running test framework self-tests..."
 
 # Run all the Python tests we find there.
 for t in *.py
 do
-    echo "`date -u`: Starting self-test: $t"
+    echo "$(date -u): Starting self-test: $t"
     SRCDIR=$RPC_TESTS_DIR/../.. python3 ./$t
-    echo "`date -u`: Finished self-test: $t"
+    echo "$(date -u): Finished self-test: $t"
     echo
 done
 
 # Return to calling folder
 
 cd "$start_folder"
 
 echo "Completed test framework self-tests."