script for keeping Go + random set of libraries up-to-date

update-go

#!/usr/bin/env bash

#########################################
# Directory structure and prerequisites #
#########################################

case "$(uname -a)" in
  *Darwin*)
    tool=brew
    ;;
  *Ubuntu* | *Debian*)
    tool=apt-get
    ;;
  *)
    echo "$(uname) is not supported" >&2
    exit
esac

type -a hg &>/dev/null || {
  ${tool} install mercurial
}

type -a bzr &>/dev/null || {
  ${tool} install python
  ${tool} install bzr
}

[ -z "${GOLANG}" ] && {
  GOLANG=${HOME}/opt/golang
}

[ -d "${GOLANG}" ] || {
  mkdir -p ${GOLANG}
  mkdir -p ${GOLANG}/pkg
  mkdir -p ${GOLANG}/bin
}

[ -d "${HOME}/.bashrc.d" ] || {
  mkdir -p "${HOME}"/.bashrc.d
  cat >>"${HOME}"/.bashrc <<EOF

###########################
# Source scripts found in #
# \${HOME}/.bashrc.d/     #
###########################

for s in \${HOME}/.bashrc.d/*; do
  [ -f "\${s}" ] && [ -x "\${s}" ] && source "\${s}";
done
EOF
}

######
# Go #
######

echo "# updating go . . ."

unset GOROOT GOPATH GOBIN
export GOROOT_FINAL="${GOLANG}"/go

[ -d "${GOROOT_FINAL}" ] && {
_tmp=$(mktemp /tmp/deploy-golang.XXXXXX)
  ( cd "${GOROOT_FINAL}"; hg pull; hg update ) 2>&1 | tee -a ${_tmp}
  REBUILD_GO=$(grep "no changes found" ${_tmp} 2>/dev/null)
} || {
  hg clone https://code.google.com/p/go "${GOROOT_FINAL}"
}

(
  [ -z "${REBUILD_GO}" ] && {
    cd "${GOROOT_FINAL}"/src
    sed -i -e '/run.bash/d' all.bash
    ./all.bash
  } || {
    true
  }
) && {
  GOCFG="${HOME}"/.bashrc.d/03-golang
  [ -f "${GOCFG}" ] || {
    cat >"${GOCFG}" <<EOF
#!/usr/bin/env bash

################################
# Go environment configuration #
################################

export GOLANG=${GOLANG}
export GOROOT=\${GOLANG}/go
export GOPATH=\${GOLANG}/pkg
export GOBIN=\${GOLANG}/bin
export PATH=\${GOROOT}/bin:\${GOBIN}:\${PATH}
EOF
  chmod +x "${GOCFG}"
  }
} || {
  exit 1
}

############
# Packages #
############

. "${GOCFG}"

pkgs=(
  code.google.com/p/go.net
  code.google.com/p/go.exp
  code.google.com/p/go.tools
  github.com/mattn/gom
  github.com/nsf/gocode
  launchpad.net/gocheck
)

for pkg in ${pkgs[@]}; do
  echo "# updating ${pkg} . . ."
  go get -u ${pkg} 
  find ${GOPATH}/src/${pkg}/cmd -depth 1 -type d 2>/dev/null |
    sed "s:${GOPATH}/src/::" | tr '\n' ' ' | xargs echo |
    while read p; do
      [ ! -z "${p}" ] && go install ${p}
    done
done