Note:/dev/null, or thebit bucket, is used as a garbage can for the command line. Unwanted output can be redirected to this location to simply make it disappear. For example, perhaps you're writing a script, and you want to test some of its functionality, but you know it will throw ...
command > fileA 2> fileB Redirect output and errors to separate files command 2>&1 >filename This will fail! Redirect to /dev/null (hide errors): command 2> /dev/null Redirect error messages to /dev/null command >/dev/null 2>&1 Redirect error and output to /dev/null ...
一、从一个c的例子讲起： void main(){ fprintf(stdout,"stdout!"); fprintf(stderr,"stderr!"...
/bin/bash# 输入主机网段read-p"请输入主机网段(例如:192.168.0.0/24): "subnet# 遍历网段中的所有IP地址foripin$(nmap -sn$subnet| grep"Nmap scan report"| awk'{print $NF}');do# Ping测试ping -c1$ip>/dev/null 2>&1if[ $? -eq 0 ];thenecho"$ipis alive"elseecho"$ipis unreachable"fid...
1 -stdout，标准输出流。 2 -stderr，标准错误流。 文件描述符只是代表打开文件的数字。 输入流通常通...
You cannot simply redirect the error output to /dev/null. The problem here is that the command is being interpreted. What if the variable value was an existing command likekillallorshutdown -h now? To prevent such an issue, you can simply use the null command as shown below. The argument...
curl -so /dev/null -w ' namelookup: %{time_namelookup}s connect: %{time_connect}s appconnect: %{time_appconnect}s pretransfer: %{time_pretransfer}s redirect: %{time_redirect}s starttransfer: %{time_starttransfer}s --- total: %{time_total}s ' https://www.baidu.com/ \ -d 'a=...
Redirect both stderr and stdout to somewhere (/dev/null perhaps?) [command] > /dev/null 2>&1 If you hit ctrl-s in a terminal, it will not display anything you type. To get the terminal back to normal, hit ctrl-q command line sequence: ...
Redirect the output of 'id' to /dev/null to suppress any output. In the main script: Check if there is exactly one argument provided (the username). If not, print usage information and exit with code 1. Next assign the provided username to the variable 'username'. ...
3.2. Redirecting File Descriptors to /dev/null Redirecting a stream to /dev/null is another way to suppress a file descriptor. /dev/null is a special virtual device file that discards all data written to it: $ exec 3>/dev/nullCopy We can redirect a stream to /dev/null when we want ...