79 lines
2.4 KiB
Go
79 lines
2.4 KiB
Go
// =============================================================================
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// Auth: Alex Celani
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// File: colonel.go
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// Revn: 06-22-2022 1.0
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// Func: Send message to another machine and then receive a single
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// response
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//
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// TODO: comment
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// =============================================================================
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// CHANGE LOG
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// -----------------------------------------------------------------------------
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// 05-04-2022: init
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// 06-20-2022: changed name to reflect first draft of colonel.go
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//*06-22-2022: bug fixing and commenting
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//
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// =============================================================================
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package main
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import (
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"net" // ResolveTCPAddr, DialTCP, conn.Write,Read
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"os" // Exit, Stdin, Stderr, Args
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"fmt" // Println, Print, Fprintf
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"bufio" // NewScanner, NewScanner.Scan,Text
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"strings" // ToLower
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)
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// quick function to take user input
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func input( ps1 string ) string {
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fmt.Print( ps1 ) // print prompt
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scanner := bufio.NewScanner( os.Stdin ) // link to stdin
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scanner.Scan() // pull data
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return strings.ToLower( scanner.Text() ) // return lower text
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}
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// quick error checking
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func check( err error ) {
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// if user checks an error, it better be nil
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if err != nil {
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// put error in string, print in stderr
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fmt.Fprintf( os.Stderr, "Fatal error: %s", err.Error() )
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os.Exit( 2 ) // quit
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}
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}
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func main() {
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// if len is not 2 ( ./name host:port ), print usage and quit
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if len( os.Args ) != 2 {
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fmt.Fprintf( os.Stderr, "Usage: %s host:port", os.Args[0] )
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os.Exit( 1 )
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}
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service := os.Args[1] // capture ip address and host
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// "resolve" ip & host according to TCP rules
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tcpAddr, err := net.ResolveTCPAddr( "tcp", service )
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check( err ) // check error
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// "dial" ( establish connection ) to destination ip & port
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// according to TCP rules
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// laddr = nil -> local address is localhost
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conn, err := net.DialTCP( "tcp", nil, tcpAddr )
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check( err ) // check error
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var in string = input( ">> " ) // get user input
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// convert user input to bytes and send over connection
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_, err = conn.Write( []byte( in ) )
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check( err ) // check error
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os.Exit( 0 ) // exeunt
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}
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