Apply technical requirements (R1, R2, R9, R10, R13)

- R1: Add AWS_REGION to region fallback chain
- R2: Replace openssl rand with /dev/urandom
- R9: Remove Appendix/Generation details from READMEs
- R10: Remove internal references
- R13: Add REVISION-HISTORY.md

Author: mwunderl

tuts/153-dynamodb-streams/REVISION-HISTORY.md

@@ -0,0 +1,8 @@
+# Revision History: 153-dynamodb-streams
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+

tuts/153-dynamodb-streams/dynamodb-streams.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-streams.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-stream-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-stream-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table with streams enabled"

tuts/162-dynamodb-continuous-backups/REVISION-HISTORY.md

@@ -0,0 +1,8 @@
+# Revision History: 162-dynamodb-continuous-backups
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+

tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-global.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-global-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-global-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table"

tuts/164-rds-snapshots/REVISION-HISTORY.md

@@ -0,0 +1,8 @@
+# Revision History: 164-rds-snapshots
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+

tuts/164-rds-snapshots/rds-snapshots.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/rds-snap.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
 echo "Step 1: Listing RDS instances"
 aws rds describe-db-instances --query 'DBInstances[:5].{Id:DBInstanceIdentifier,Engine:Engine,Status:DBInstanceStatus,Class:DBInstanceClass}' --output table 2>/dev/null || echo "  No RDS instances"
 echo "Step 2: Listing automated snapshots"

tuts/168-dynamodb-queries/REVISION-HISTORY.md

@@ -0,0 +1,8 @@
+# Revision History: 168-dynamodb-queries
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+

tuts/168-dynamodb-queries/dynamodb-queries.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-query.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-query-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-query-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table with GSI"

tuts/173-dynamodb-ttl/REVISION-HISTORY.md

@@ -0,0 +1,8 @@
+# Revision History: 173-dynamodb-ttl
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+

tuts/173-dynamodb-ttl/dynamodb-ttl.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ttl.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-ttl-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-ttl-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table"