adding repl_cmds

shell/repl_cmds.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+#
+# SPDX-License-Identifier: MIT
+
+# if resize (via xterm) is not available
+alias tsize='shopt -s checkwinsize;COLUMNS=$(tput cols);LINES=$(tput lines);export COLUMNS LINES;echo -e "COLUMNS=$COLUMNS;\nLINES=$LINES;\nexport COLUMNS LINES;"'
+
+# if netcat is not available
+# - requires --enable-net-redirections compiled in with bash
+# - works on RHEL/CentOS/Fedora but not Ubuntu/Debian
+function nctzv() { [[ $# -eq 2 ]] && (timeout 3 bash -c "echo >/dev/tcp/$1/$2" && echo "Connection to $1 port $2/tcp succeeded" || echo "Connection to $1 port $2/tcp failed"); }
+
+# the same nctzv() function in perl
+function nctzv_pl() { perl -e 'use IO::Socket::INET;$socket=IO::Socket::INET->new(Proto=>tcp,Timeout=>3,PeerAddr=>$ARGV[0],PeerPort=>$ARGV[1]);printf("Connection to %s port %s/tcp ",$ARGV[0],$ARGV[1]);if(defined $socket && $socket){$socket->close();print "succeeded\n"}else{print "failed\n";}' "$1" "$2"; }
+
+# the same nctzv() function in python
+function nctzv_py() { python -c "exec('import sys\nimport socket\nh=sys.argv[1]\np=sys.argv[2]\ns=socket.socket(socket.AF_INET,socket.SOCK_STREAM)\ns.settimeout(3)\ntry:\n\ts.connect((sys.argv[1],int(sys.argv[2])))\n\ts.shutdown(2)\n\tprint \"Connection to \"+h+\" port \"+p+\"/tcp succeeded\"\nexcept:\n\tprint \"Connection to \"+h+\" port \"+p+\"/tcp failed\"\ns.close')" "$1" "$2"; }