I'm have started to learn batch programming to go a little more deeper in the Windows Machines. In Internet I have seen some commands with echo like "@echo off" or "on" and also this: "echo." but I don't know what are they doing. If anyone can explain me the functions of the echo command, please answer me.
3 Answers
The ECHO command in Windows CMD is used to print out text to the screen, display the actual setting of the Command-line which means when you do:
@echo off The "C:\Users[User]" line before your command input will disappear. You can restore it with:
@echo on Here all functions of ECHO explained:
@echo [on/off] (to set the command-line settings)
echo [text] (to print text to the screen)
echo. (to print an empty line to the screen)
echo (displays the current setting of the command-line)
echo /? (displays help for the command ECHO)
I hope I was able to help you.
5 Comments
@echo on is also useful to debug batch scripts, to see what's going on when something seems not to work.echo(, as said by dbenham it always works (stackoverflow.com/a/3123194).@echo off in top of any script, but at development time, is helpful to turn it on above a problematic section of code to see command expansion and its output. of course, once the bug or typo is corrected, it must be removed.@echo. .. error why cannot use administrator?By default, every command executed in a batch file is also echoed to the output - not just the output of the command, but the command itself.
The echo command has three modes:
- When called with some arguments AFTER a space, it will output the arguments.
- When called as
echo.(no space) it will output just a blank line. - When called with just the arguments on or off, it controls the behaviour of printing the commands as they execute.
So, the echo off command turns off the output at the start of the batch file. However, that command itself is still echoed before it has a chance to turn off the echoing. The @ symbol has the effect of turning off the output for only the current command.
Combining the two, the @echo off at the start of a batch file turns off the echoing without itself being echoed.
It follows from this that if you try to echo just the word off, without quotes, it will turn off command printing instead. If you try to work around this by quoting the word "off", the output will include the quotes. The answer, thanks to @JeffZeitlin's comment below, is:
In the presumably unusual case of wanting to echo just the word off or on (i.e., not a part of any other string), it turns out that echo.off and echo.on do the trick.
3 Comments
echo.off and echo.on do the trick.echo. The "." isn't a whitespace character, so it won't parse echo.on as the echo on command. Next this trick takes advantage of how the echo command assumes that the first character in the argument string is white space to be skipped over, except in this case it's skipping the ".".Partial answer is this: What does "@" mean in Windows batch scripts
The @ before the command means do not print that command when running it.
The off argument tells the script not output any other commands, however without the @ would output the echo off (since echoing hasn't yet been turned off)
The on argument turns command echoing back on.
Any other arguments are just echoed to the display
/?- in this case, you'd typeecho /?