[Refactor] prefer case over if/else chains

nvm.sh

@@ -63,11 +63,13 @@ nvm_command_info() {
   local INFO
   COMMAND="${1}"
   if type "${COMMAND}" | nvm_grep -q hashed; then
-    INFO="$(type "${COMMAND}" | command awk '{ gsub(/[()]/,""); print $4 }')"
+    INFO="$(type "${COMMAND}" | command sed -E 's/\(|\)//g' | command awk '{print $4}')"
   elif type "${COMMAND}" | nvm_grep -q aliased; then
-    INFO="$(which "${COMMAND}") ($(type "${COMMAND}" | command awk "{ \$1=\$2=\$3=\$4=\"\"; sub(/^ */, \"\"); gsub(/[\\\`']/, \"\"); print}"))"
+    # shellcheck disable=SC2230
+    INFO="$(which "${COMMAND}") ($(type "${COMMAND}" | command awk '{ $1=$2=$3=$4="" ;print }' | command sed -e 's/^\ *//g' -Ee "s/\`|'//g"))"
   elif type "${COMMAND}" | nvm_grep -q "^${COMMAND} is an alias for"; then
-    INFO="$(which "${COMMAND}") ($(type "${COMMAND}" | command awk "{ \$1=\$2=\$3=\$4=\$5=\"\"; sub(/^ */, \"\"); print }"))"
+    # shellcheck disable=SC2230
+    INFO="$(which "${COMMAND}") ($(type "${COMMAND}" | command awk '{ $1=$2=$3=$4=$5="" ;print }' | command sed 's/^\ *//g'))"
   elif type "${COMMAND}" | nvm_grep -q "^${COMMAND} is /"; then
     INFO="$(type "${COMMAND}" | command awk '{print $3}')"
   else
@@ -85,7 +87,7 @@ nvm_has_colors() {
 }
 
 nvm_curl_libz_support() {
-  curl -V 2>/dev/null | command awk '/^Features:.*libz/ { found=1; exit } END { exit (found ? 0 : 1) }'
+  curl -V 2>/dev/null | nvm_grep "^Features:" | nvm_grep -q "libz"
 }
 
 nvm_curl_use_compression() {
@@ -532,13 +534,9 @@ $(nvm_wrap_with_color_code 'y' "${warn_text}")"
 nvm_process_nvmrc() {
   local NVMRC_PATH
   NVMRC_PATH="$1"
-
   local lines
-  lines=$(command awk '{
-    sub(/#.*/, "")
-    gsub(/^[[:space:]]+|[[:space:]]+$/, "")
-    if (length($0) > 0) print
-  }' "$NVMRC_PATH")
+
+  lines=$(command sed 's/#.*//' "$NVMRC_PATH" | command sed 's/^[[:space:]]*//;s/[[:space:]]*$//' | nvm_grep -v '^$')
 
   if [ -z "$lines" ]; then
     nvm_nvmrc_invalid_msg "${lines}"
@@ -1417,11 +1415,11 @@ nvm_add_iojs_prefix() {
 nvm_strip_iojs_prefix() {
   local NVM_IOJS_PREFIX
   NVM_IOJS_PREFIX="$(nvm_iojs_prefix)"
-  if [ "${1-}" = "${NVM_IOJS_PREFIX}" ]; then
-    nvm_echo
-  else
-    nvm_echo "${1#"${NVM_IOJS_PREFIX}"-}"
-  fi
+
+  case "${1-}" in
+    "${NVM_IOJS_PREFIX}") nvm_echo ;;
+    *) nvm_echo "${1#"${NVM_IOJS_PREFIX}"-}" ;;
+  esac
 }
 
 nvm_ls() {
@@ -1553,12 +1551,15 @@ nvm_ls() {
   fi
 
   if [ "${NVM_ADD_SYSTEM-}" = true ]; then
-    if [ -z "${PATTERN}" ] || [ "${PATTERN}" = 'v' ]; then
-      VERSIONS="${VERSIONS}
+    case "${PATTERN}" in
+      '' | v)
+        VERSIONS="${VERSIONS}
 system"
-    elif [ "${PATTERN}" = 'system' ]; then
-      VERSIONS="system"
-    fi
+      ;;
+      system)
+        VERSIONS="system"
+      ;;
+    esac
   fi
 
   if [ -z "${VERSIONS}" ]; then
@@ -1692,7 +1693,7 @@ EOF
     LTS="${LTS#lts/}"
   fi
 
-  VERSIONS="$({ command awk -v lts="${LTS-}" '{
+  VERSIONS="$( { command awk -v lts="${LTS-}" '{
         if (!$1) { next }
         if (lts && $10 ~ /^\-?$/) { next }
         if (lts && lts != "*" && tolower($10) !~ tolower(lts)) { next }
@@ -1997,28 +1998,7 @@ nvm_print_implicit_alias() {
       NVM_IOJS_VERSION="$(${NVM_COMMAND})" &&:
       EXIT_CODE="$?"
       if [ "_${EXIT_CODE}" = "_0" ]; then
-        NVM_IOJS_VERSION="$(nvm_echo "${NVM_IOJS_VERSION}" | command awk -v prefix="^${NVM_IMPLICIT}-" '
-          BEGIN {
-            last = ""
-            prev = ""
-          }
-          {
-            sub(prefix, "")
-            # skip lines that do not start with "v"
-            if ($0 !~ /^v/) next
-            # remove leading "v"
-            sub(/^v/, "")
-            # keep only major.minor
-            split($0, parts, "\\.")
-            short = parts[1] "." parts[2]
-            # replicate "uniq" by only updating if changed
-            if (short != prev) {
-              last = short
-              prev = short
-            }
-          }
-          END { print last }
-        ')"
+        NVM_IOJS_VERSION="$(nvm_echo "${NVM_IOJS_VERSION}" | command sed "s/^${NVM_IMPLICIT}-//" | nvm_grep -e '^v' | command cut -c2- | command cut -d . -f 1,2 | uniq | command tail -1)"
       fi
 
       if [ "_$NVM_IOJS_VERSION" = "_N/A" ]; then
@@ -2040,7 +2020,7 @@ nvm_print_implicit_alias() {
 
       nvm_is_zsh && setopt local_options shwordsplit
 
-      LAST_TWO="$($NVM_COMMAND | command awk '/^v/ { sub(/^v/, ""); split($0, parts, "\\."); short=parts[1]"."parts[2]; if (!seen[short]++) print short }')"
+      LAST_TWO=$($NVM_COMMAND | nvm_grep -e '^v' | command cut -c2- | command cut -d . -f 1,2 | uniq)
     ;;
   esac
   local MINOR
@@ -2757,19 +2737,13 @@ nvm_npm_global_modules() {
   local NPMLIST
   local VERSION
   VERSION="$1"
-  NPMLIST="$(nvm use "${VERSION}" >/dev/null && npm list -g --depth=0 2>/dev/null | command awk 'NR == 1 { next } /UNMET PEER DEPENDENCY/ { next } { print }')"
+  NPMLIST=$(nvm use "${VERSION}" >/dev/null && npm list -g --depth=0 2>/dev/null | command sed -e '1d' -e '/UNMET PEER DEPENDENCY/d')
 
   local INSTALLS
-  INSTALLS="$(nvm_echo "${NPMLIST}" | command awk '
-      / -> /         { next }
-      /\(empty\)/    { next }
-      /^npm@/        { next }
-      { sub(/^.* (.*@[^ ]*).*/,"\\1"); if (length($0) > 0) print }
-    ' | command xargs
-  )"
+  INSTALLS=$(nvm_echo "${NPMLIST}" | command sed -e '/ -> / d' -e '/\(empty\)/ d' -e 's/^.* \(.*@[^ ]*\).*/\1/' -e '/^npm@[^ ]*.*$/ d' | command xargs)
 
   local LINKS
-  LINKS="$(nvm_echo "${NPMLIST}" | command awk '/ -> / { sub(/.* -> /,""); print } ')"
+  LINKS="$(nvm_echo "${NPMLIST}" | command sed -n 's/.* -> \(.*\)/\1/ p')"
 
   nvm_echo "${INSTALLS} //// ${LINKS}"
 }