export-json.bash WIP

1 files changed, 103 insertions, 0 deletions

diff --git a/wordpress/export-json.bash b/wordpress/export-json.bash
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+#!/bin/bash
+
+# This script allows bash to export environment
+# variables as JSON. It uses the external tool
+# "jq" to parse string values # placed in jq's
+# argument list by bash and then encode them
+# as JSON string values. This is no accidental
+# dependency. The jq program is the foundation of
+# the trustworthiness of this code. If we were
+# encoding JSON strings in bash (and not just JSON
+# objects containing strings) we would have to be
+# a lot more careful.
+
+# This is the simple code I wanted to replace:
+#
+# jq --arg SITE "$SITE" "$json"
+# jq -n \
+#       --arg h "$db_host" \
+#       --arg u "$db_user" \
+#       --arg p "$db_password" \
+#       --arg n "$db_name" \
+#       --arg t "$table_prefix" \
+#       '{ db_host: $h
+#        , db_user: $u
+#        , db_password: $p
+#        , db_name: $n
+#        , table_prefix: $t
+#        }'
+#
+# The problem with the above is that the names are repeated.
+# This creates the possibility that the names not match,
+# creating a bug.
+# This code allows the names to be specified only one time.
+# It allows the bug where the names do not match to be fixed only one
+# time by one person.
+# IF ... the fix can be distributed back to the extant copies.
+# How to get the beneficial mutations
+# back into the living organisms?
+# Life tries not to answer this question
+# until very late in its development
+# since after all
+# the extant copies are the past
+# and life looks into the future
+# but because consciousness
+# is the mirror of time
+# the question is asked
+# eventually
+
+export_JSON()
+{
+        declare -a exported_vars=()
+        declare -A displayname=()
+        while [ $# -gt 0 ]
+        do
+                case "$1" in
+                        v | exported_vars | displayname | jqargs | jqjson | n )
+                                continue
+                                ;;
+                        *[^a-zA-Z0-9_=]* | *=*=* )
+                                continue
+                                ;;
+                        [a-zA-Z_]*=* )
+                                exported_vars+=("${1%=*}")
+                                displayname["${1%=*}"]=${1#*=}
+                                ;;
+                        [a-zA-Z_]* )
+                                exported_vars+=("$1")
+                                ;;
+                esac
+                shift
+        done
+        export_with_jq
+}
+
+export_with_jq()
+{
+        n=$'\n'
+        jqargs=("-n")
+        jqjson=
+        for v in "${exported_vars[@]}"
+        do
+                if ! [ -v "$v" ]
+                then
+                        echo "Warning: not defined: $v" >&2
+                        continue
+                fi
+                jqargs+=(--arg "$v" "${!v}")
+                if [ "$jqjson" ]
+                then
+                        p=','
+                else
+                        p='{'
+                fi
+                dv=${displayname[$v]}
+                jqjson="$jqjson$p ${dv:-$v}: \$$v$n"
+        done
+        if [ "$jqjson" ]
+        then
+                jqjson="$jqjson}$n"
+        fi
+        jq -n "${jqargs[@]}" "$jqjson"
+}
+