Satisfied all remaining shellcheck warnings:

* Replaced all remaining $.. with "$..".

* Replaced raw $? checks with better  ||, && and "if" checks.

* Packed chains of 'echo ".." >> $x; echo ".." >> $x' with better
  '{ echo ".."; echo ".." } >> $x'.

* exported locally unused variables (that are probably needed by other
  scripts).

src/alert_methods/SCP/alert

@@ -27,7 +27,7 @@ PASSWORD_FILE=$6
 REPORT_FILE=$7
 
 KNOWN_HOSTS_FILE=$(mktemp) || exit 1
-echo $KNOWN_HOSTS > $KNOWN_HOSTS_FILE
+echo "$KNOWN_HOSTS" > "$KNOWN_HOSTS_FILE"
 
 ERROR_FILE=$(mktemp) || exit 1
 
@@ -55,9 +55,9 @@ DEST_ESC=$(shell_esc "$DEST")
 
 if [ -z "$PRIVATE_KEY_FILE" ]
 then
-  timeout $TIMEOUT sshpass -f ${PASSWORD_FILE} scp -o HashKnownHosts=no -o UserKnownHostsFile="${KNOWN_HOSTS_FILE} ~/.ssh/known_hosts ~/.ssh/known_hosts2 /etc/ssh/ssh_known_hosts" "${REPORT_FILE}" "${USERNAME}@${HOST}:${DEST_ESC}" 2>$ERROR_FILE
+  timeout "$TIMEOUT" sshpass -f "${PASSWORD_FILE}" scp -o HashKnownHosts=no -o UserKnownHostsFile="${KNOWN_HOSTS_FILE} ~/.ssh/known_hosts ~/.ssh/known_hosts2 /etc/ssh/ssh_known_hosts" "${REPORT_FILE}" "${USERNAME}@${HOST}:${DEST_ESC}" 2>"$ERROR_FILE"
 else
-  timeout $TIMEOUT sshpass -f ${PASSWORD_FILE} -P "passphrase" scp -i "$PRIVATE_KEY_FILE" -o PasswordAuthentication=no -o HashKnownHosts=no -o UserKnownHostsFile="${KNOWN_HOSTS_FILE} ~/.ssh/known_hosts ~/.ssh/known_hosts2 /etc/ssh/ssh_known_hosts" "${REPORT_FILE}" "${USERNAME}@${HOST}:${DEST_ESC}" 2>"$ERROR_FILE"
+  timeout "$TIMEOUT" sshpass -f "${PASSWORD_FILE}" -P "passphrase" scp -i "$PRIVATE_KEY_FILE" -o PasswordAuthentication=no -o HashKnownHosts=no -o UserKnownHostsFile="${KNOWN_HOSTS_FILE} ~/.ssh/known_hosts ~/.ssh/known_hosts2 /etc/ssh/ssh_known_hosts" "${REPORT_FILE}" "${USERNAME}@${HOST}:${DEST_ESC}" 2>"$ERROR_FILE"
 fi
 
 EXIT_CODE=$?
@@ -93,8 +93,8 @@ then
   log_error "sshpass failed with exit code ${EXIT_CODE}: $ERROR_SHORT"
 fi
 
-rm $KNOWN_HOSTS_FILE
-rm $PASSWORD_FILE
-rm $ERROR_FILE
+rm "$KNOWN_HOSTS_FILE"
+rm "$PASSWORD_FILE"
+rm "$ERROR_FILE"
 
 exit $EXIT_CODE

src/alert_methods/SNMP/alert

@@ -22,12 +22,12 @@ COMMUNITY=$1
 AGENT=$2  # Host.
 MESSAGE=$3
 
-OUTPUT=$(snmptrap -v 2c -c $COMMUNITY $AGENT '' .1.3.6.1.6.3 0 s "$MESSAGE" 2>&1)
+OUTPUT=$(snmptrap -v 2c -c "$COMMUNITY" "$AGENT" '' .1.3.6.1.6.3 0 s "$MESSAGE" 2>&1)
 
 EXIT_CODE=$?
 
 if [ "0" -ne "$EXIT_CODE" ]
 then
-  echo "snmptrap failed with code $EXIT_CODE:\n$OUTPUT" >&2
+  printf 'snmptrap failed with code %s:\n%s\n' "$EXIT_CODE" "$OUTPUT">&2
   exit $EXIT_CODE
 fi

src/alert_methods/Send/alert

@@ -18,6 +18,6 @@
 
 # Escalator method script: Send.
 
-cat $3 | socat -t 0 - TCP:$1:$2
+socat -t 0 - TCP:"$1":"$2" < "$3"
 EXIT_CODE=$?
 exit $EXIT_CODE

src/alert_methods/Sourcefire/alert

@@ -18,6 +18,6 @@
 
 # Escalator method script: Sourcefire connector.
 
-greenbone_sourcefire_connector -server=$1 -port=$2 -pkcs12=$3 -password="$5" $4
+greenbone_sourcefire_connector -server="$1" -port="$2" -pkcs12="$3" -password="$5" "$4"
 EXIT_CODE=$?
 exit $EXIT_CODE

src/alert_methods/verinice/alert

@@ -18,6 +18,6 @@
 
 # Escalator method script: verinice connector.
 
-greenbone_verinice_connector $1 $2 $3 $4
+greenbone_verinice_connector "$1" "$2" "$3" "$4"
 EXIT_CODE=$?
 exit $EXIT_CODE

src/schema_formats/HTML/generate

@@ -21,4 +21,4 @@
 # This schema generator creates a single HTML file from the XML schema using
 # an XSL transformation via the tool xsltproc.
 
-xsltproc ./HTML.xsl $1
+xsltproc ./HTML.xsl "$1"

src/schema_formats/RNC/generate

@@ -21,4 +21,4 @@
 # This schema generator creates a single RNC file from the XML schema using
 # an XSL transformation via the tool xsltproc.
 
-xsltproc ./RNC.xsl $1
+xsltproc ./RNC.xsl "$1"

src/schema_formats/XML-brief/generate

@@ -21,4 +21,4 @@
 # This schema generator creates a brief XML description of the protocol.
 # Basically just the command list.
 
-xsltproc ./GMP.xsl $1
+xsltproc ./GMP.xsl "$1"

src/schema_formats/XML/generate

@@ -21,5 +21,5 @@
 # This schema generator is the most trivial one as it simply passes on the
 # GMP XML schema as is.
 
-cat $1
+cat "$1"
 exit 0