fix(systemadmin): make the netstat fallback reachable

Six helpers were written as `ss ... | awk ... || netstat ... | awk ...`.
A pipeline exits with its last command's status, so a missing ss still
ended in awk exiting 0 and the netstat branch never ran. On systems
without ss, sortcons, sortconip, req20, timewait20, syn20 and port_pro
printed nothing.

Each helper now picks ss or netstat by whether ss is installed. con80
gets the same shape so the file has one idiom and no longer prints
"command not found: ss" on the way to netstat. Where both backends
share the same columns, the awk program is written once.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

plugins/systemadmin/systemadmin.plugin.zsh

@@ -65,37 +65,43 @@ fi
 
 # Sort connection state
 function sortcons() {
-  {
-    LANG= ss -nat | awk 'NR > 1 {print $1}' \
-    || LANG= netstat -nat | awk 'NR > 2 {print $6}'
-  } | sort | uniq -c | sort -rn
+  if (( $+commands[ss] )); then
+    LANG= ss -nat | awk 'NR > 1 {print $1}'
+  else
+    LANG= netstat -nat | awk 'NR > 2 {print $6}'
+  fi | sort | uniq -c | sort -rn
 }
 
 # View all connections on the given ports (default 80 and 443)
 function con80() {
   local -a ports=($@)
   (( $# )) || ports=(80 443)
-  {
-    LANG= ss -nat || LANG= netstat -nat
-  } | grep -E ":(${(j:|:)ports})[^0-9]" | wc -l
+  if (( $+commands[ss] )); then
+    LANG= ss -nat
+  else
+    LANG= netstat -nat
+  fi | grep -E ":(${(j:|:)ports})[^0-9]" | wc -l
 }
 
 # On the connected IP sorted by the number of connections
 function sortconip() {
-  {
-    LANG= ss -ntu | awk 'NR > 1 {print $6}' \
-    || LANG= netstat -ntu | awk 'NR > 2 {print $5}'
-  } | cut -d: -f1 | sort | uniq -c | sort -n
+  if (( $+commands[ss] )); then
+    LANG= ss -ntu | awk 'NR > 1 {print $6}'
+  else
+    LANG= netstat -ntu | awk 'NR > 2 {print $5}'
+  fi | cut -d: -f1 | sort | uniq -c | sort -n
 }
 
 # top20 of Find the number of requests on the given ports (default 80 and 443)
 function req20() {
   local -a ports=($@)
   (( $# )) || ports=(80 443)
-  {
-    LANG= ss -tn | awk -v ports="${(j:|:)ports}" '$4 ~ ":("ports")$" {print $5}' \
-    || LANG= netstat -tn | awk -v ports="${(j:|:)ports}" '$4 ~ ":("ports")$" {print $5}'
-  } | awk -F: '{print $1}' | sort | uniq -c | sort -nr | head -n 20
+  if (( $+commands[ss] )); then
+    LANG= ss -tn
+  else
+    LANG= netstat -tn
+  fi | awk -v ports="${(j:|:)ports}" '$4 ~ ":("ports")$" {print $5}' \
+    | awk -F: '{print $1}' | sort | uniq -c | sort -nr | head -n 20
 }
 
 # top20 of Using tcpdump to view access to the given ports (default 80 and 443)
@@ -107,24 +113,29 @@ function http20() {
 
 # top20 of Find time_wait connection
 function timewait20() {
-  {
-    LANG= ss -nat | awk 'NR > 1 && /TIME-WAIT/ {print $5}' \
-    || LANG= netstat -nat | awk 'NR > 2 && /TIME_WAIT/ {print $5}'
-  } | sort | uniq -c | sort -rn | head -n 20
+  if (( $+commands[ss] )); then
+    LANG= ss -nat
+  else
+    LANG= netstat -nat
+  fi | awk '/TIME[-_]WAIT/ {print $5}' | sort | uniq -c | sort -rn | head -n 20
 }
 
 # top20 of Find SYN connection
 function syn20() {
-  {
-    LANG= ss -an | awk '/SYN/ {print $5}' \
-    || LANG= netstat -an | awk '/SYN/ {print $5}'
-  } | awk -F: '{print $1}' | sort | uniq -c | sort -nr | head -n20
+  if (( $+commands[ss] )); then
+    LANG= ss -an
+  else
+    LANG= netstat -an
+  fi | awk '/SYN/ {print $5}' | awk -F: '{print $1}' | sort | uniq -c | sort -nr | head -n20
 }
 
 # Printing process according to the port number
 function port_pro() {
-  LANG= ss -ntlp | awk "NR > 1 && /:${1:-}/ {print \$6}" | sed 's/.*pid=\([^,]*\).*/\1/' \
-  || LANG= netstat -ntlp | awk "NR > 2 && /:${1:-}/ {print \$7}" | cut -d/ -f1
+  if (( $+commands[ss] )); then
+    LANG= ss -ntlp | awk "NR > 1 && /:${1:-}/ {print \$6}" | sed 's/.*pid=\([^,]*\).*/\1/'
+  else
+    LANG= netstat -ntlp | awk "NR > 2 && /:${1:-}/ {print \$7}" | cut -d/ -f1
+  fi
 }
 
 # top10 of gain access to the ip address