mika · September 6, 2017 08:55 · Jul 31, 2015 · Jul 31, 2015 · Jul 31, 2015 · Jul 31, 2015
diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -42,7 +42,9 @@ function get_mx() {
   unzip "${top1m_zip}" &> /dev/null
 }
 
-[[ ${1} == "get_mx" ]] && { get_mx "${2}" && exit 0 }
+[[ ${1} == "get_mx" ]] && { 
+  get_mx "${2}" && exit 0 
+}
 
 if [[ $(which parallel) ]]; then
   printf "<< parallel mode >>\n\n" >&2

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -42,9 +42,7 @@ function get_mx() {
   unzip "${top1m_zip}" &> /dev/null
 }
 
-[[ ${1} == "get_mx" ]] && {
-  get_mx "${2}" && exit 0
-}
+[[ ${1} == "get_mx" ]] && { get_mx "${2}" && exit 0 }
 
 if [[ $(which parallel) ]]; then
   printf "<< parallel mode >>\n\n" >&2

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -43,8 +43,7 @@ function get_mx() {
 }
 
 [[ ${1} == "get_mx" ]] && {
-  get_mx "${2}" || exit 1
-  exit 0
+  get_mx "${2}" && exit 0
 }
 
 if [[ $(which parallel) ]]; then

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -51,7 +51,7 @@ if [[ $(which parallel) ]]; then
   printf "<< parallel mode >>\n\n" >&2
   parallel --progress --colsep ',' "${0} get_mx {2}" :::: ${top1m_csv}
 else
-  printf "<< sequential mode (slow! install \`parallel\` for speed.) >>\n\n" >&2
+  printf "<< sequential mode (slow! install \`parallel\`.) >>\n\n" >&2
   for host in $(hosts); do
     get_mx "${host}"
   done

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -51,7 +51,7 @@ if [[ $(which parallel) ]]; then
   printf "<< parallel mode >>\n\n" >&2
   parallel --progress --colsep ',' "${0} get_mx {2}" :::: ${top1m_csv}
 else
-  printf "<< sequential mode (fuck-slow!) >>\n\n" >&2
+  printf "<< sequential mode (slow! install \`parallel\` for speed.) >>\n\n" >&2
   for host in $(hosts); do
     get_mx "${host}"
   done

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -30,7 +30,7 @@ function get_mx() {
                       +time=2 mx "${1}" | sed 's/.*\ //'))
   printf '{\n\t"%s": {\n\t\t"mx_records": [\n' "${1}"
   for mx in "${mx_records[@]}"; do
-    local ip=($(getent ahostsv4 ${mx})) # we only need v4 for scanning
+    local ip=($(getent ahostsv4 ${mx})) # in our case, v4 suffices.
     printf '\t\t\t"%s":   \t"%s",\n' "${mx}" "${ip}"
   done
   printf "\t\t]\n\t}\n}\n"

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -9,7 +9,7 @@
 # Authors: Aaron Zauner <[email protected]>
 # License: CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0)
 #
-set -e pipefail
+set -eo pipefail
 
 readonly top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 readonly top1m_zip=${top1m_s3l##*/}

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -9,7 +9,7 @@
 # Authors: Aaron Zauner <[email protected]>
 # License: CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0)
 #
-set -e
+set -e pipefail
 
 readonly top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 readonly top1m_zip=${top1m_s3l##*/}

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -58,4 +58,4 @@ else
 fi
 trap '{ rm ${top1m_zip} ${top1m_csv};   \
         printf "\n\n<< finished run. >> \
-        $(date --rfc-3339=ns).\n" >&2   }' EXIT
+        $(date --rfc-3339=ns)   \n" >&2 }' EXIT
diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -56,5 +56,6 @@ else
     get_mx "${host}"
   done
 fi
-trap '{ rm ${top1m_zip} ${top1m_csv};      \
-        printf "\n\n<< finished. >>\n" >&2 }' EXIT
+trap '{ rm ${top1m_zip} ${top1m_csv};   \
+        printf "\n\n<< finished run. >> \
+        $(date --rfc-3339=ns).\n" >&2   }' EXIT
diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -2,7 +2,8 @@
 #
 # Retrieves MX and A records for 'Alexa Top 1 Million' hosts
 # and prints them as pretty formatted JSON objects to stdout.
-# Optional parallelism support with GNU Parallel (recommended):
+#
+# *Optional* parallelism support with GNU Parallel (recommended):
 #     $ sudo apt-get install parallel
 #
 # Authors: Aaron Zauner <[email protected]>

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 #
-# Retrieves MX and A records for 'Alexa Top 1 Million' list
-# and prints them as nicely formatted JSON object to stdout.
+# Retrieves MX and A records for 'Alexa Top 1 Million' hosts
+# and prints them as pretty formatted JSON objects to stdout.
 # Optional parallelism support with GNU Parallel (recommended):
 #     $ sudo apt-get install parallel
 #

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -3,7 +3,7 @@
 # Retrieves MX and A records for 'Alexa Top 1 Million' list
 # and prints them as nicely formatted JSON object to stdout.
 # Optional parallelism support with GNU Parallel (recommended):
-#   `sudo apt-get install parallel`
+#     $ sudo apt-get install parallel
 #
 # Authors: Aaron Zauner <[email protected]>
 # License: CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0)

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -2,7 +2,7 @@
 #
 # Retrieves MX and A records for 'Alexa Top 1 Million' list
 # and prints them as nicely formatted JSON object to stdout.
-# Optionally supports GNU Parallel (recommended):
+# Optional parallelism support with GNU Parallel (recommended):
 #   `sudo apt-get install parallel`
 #
 # Authors: Aaron Zauner <[email protected]>

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -29,7 +29,7 @@ function get_mx() {
                       +time=2 mx "${1}" | sed 's/.*\ //'))
   printf '{\n\t"%s": {\n\t\t"mx_records": [\n' "${1}"
   for mx in "${mx_records[@]}"; do
-    local ip=($(getent ahostsv4 ${mx})) # only need v4 for scanning
+    local ip=($(getent ahostsv4 ${mx})) # we only need v4 for scanning
     printf '\t\t\t"%s":   \t"%s",\n' "${mx}" "${ip}"
   done
   printf "\t\t]\n\t}\n}\n"

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -29,7 +29,7 @@ function get_mx() {
                       +time=2 mx "${1}" | sed 's/.*\ //'))
   printf '{\n\t"%s": {\n\t\t"mx_records": [\n' "${1}"
   for mx in "${mx_records[@]}"; do
-    local ip=($(getent ahostsv4 ${mx}))
+    local ip=($(getent ahostsv4 ${mx})) # only need v4 for scanning
     printf '\t\t\t"%s":   \t"%s",\n' "${mx}" "${ip}"
   done
   printf "\t\t]\n\t}\n}\n"

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -10,9 +10,9 @@
 #
 set -e
 
-top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
-top1m_zip=${top1m_s3l##*/}
-top1m_csv=${top1m_zip%.*}
+readonly top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
+readonly top1m_zip=${top1m_s3l##*/}
+readonly top1m_csv=${top1m_zip%.*}
 
 function hosts() {
   for line in $(<${top1m_csv}); do

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -55,5 +55,5 @@ else
     get_mx "${host}"
   done
 fi
-trap '{ rm ${top1m_zip} ${top1m_csv};    \
-        printf "\n\n<<finished.>>\n" >&2 }' EXIT
+trap '{ rm ${top1m_zip} ${top1m_csv};      \
+        printf "\n\n<< finished. >>\n" >&2 }' EXIT
diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,8 +13,6 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{ rm ${top1m_zip} ${top1m_csv};    \
-        printf "\n\n<<finished.>>\n" >&2 }' EXIT
 
 function hosts() {
   for line in $(<${top1m_csv}); do
@@ -56,4 +54,6 @@ else
   for host in $(hosts); do
     get_mx "${host}"
   done
-fi
+fi
+trap '{ rm ${top1m_zip} ${top1m_csv};    \
+        printf "\n\n<<finished.>>\n" >&2 }' EXIT
diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -14,7 +14,7 @@ top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
 trap '{ rm ${top1m_zip} ${top1m_csv};    \
-        printf "\n\n<<finished.>>\n" >&2}' EXIT
+        printf "\n\n<<finished.>>\n" >&2 }' EXIT
 
 function hosts() {
   for line in $(<${top1m_csv}); do

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,7 +13,7 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{ rm ${top1m_zip} ${top1m_csv};  \
+trap '{ rm ${top1m_zip} ${top1m_csv};    \
         printf "\n\n<<finished.>>\n" >&2}' EXIT
 
 function hosts() {

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,7 +13,7 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{ rm ${top1m_zip} ${top1m_csv};    \
+trap '{ rm ${top1m_zip} ${top1m_csv};  \
         printf "\n\n<<finished.>>\n" >&2}' EXIT
 
 function hosts() {

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,7 +13,7 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{ rm ${top1m_zip} ${top1m_csv} ;   \
+trap '{ rm ${top1m_zip} ${top1m_csv};    \
         printf "\n\n<<finished.>>\n" >&2}' EXIT
 
 function hosts() {

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,7 +13,7 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{ rm ${top1m_zip} ${top1m_csv} ;  \
+trap '{ rm ${top1m_zip} ${top1m_csv} ;   \
         printf "\n\n<<finished.>>\n" >&2}' EXIT
 
 function hosts() {

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,7 +13,7 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{ rm ${top1m_zip} ${top1m_csv} ;\
+trap '{ rm ${top1m_zip} ${top1m_csv} ;  \
         printf "\n\n<<finished.>>\n" >&2}' EXIT
 
 function hosts() {

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -13,7 +13,8 @@ set -e
 top1m_s3l="https://s3.amazonaws.com/alexa-static/top-1m.csv.zip"
 top1m_zip=${top1m_s3l##*/}
 top1m_csv=${top1m_zip%.*}
-trap '{rm ${top1m_zip} ${top1m_csv} ; printf "\n\n<<finished.>>\n" >&2}' EXIT
+trap '{ rm ${top1m_zip} ${top1m_csv} ;\
+        printf "\n\n<<finished.>>\n" >&2}' EXIT
 
 function hosts() {
   for line in $(<${top1m_csv}); do

diff --git a/get_alexa_1m_mx_rrs b/get_alexa_1m_mx_rrs
@@ -50,8 +50,6 @@ function get_mx() {
 if [[ $(which parallel) ]]; then
   printf "<< parallel mode >>\n\n" >&2
   parallel --progress --colsep ',' "${0} get_mx {2}" :::: ${top1m_csv}
-  trap INT HUP '{ echo "singal! exiting early, keeping files" ; exit 1 }'
-  rm ${top1m_zip} ${top1m_csv}
 else
   printf "<< sequential mode (fuck-slow!) >>\n\n" >&2
   for host in $(hosts); do