last=$(echo `history |tail -n2 |head -n1` | sed 's/[0-9]* //') echo "last command is [$last]" case "1" in "1") date last=$(echo `history |tail -n2 |head -n1` | sed 's/[0-9]* //') echo "last command is [$last]" ;; esac 输出: Tue May 24 12:36:04 CEST...
If no COMMAND is specified the WGET_ASKPASS or the SSH_ASKPASS environment variable is used. --no-iri turn off IRI support --local-encoding=ENC use ENC as the local encoding for IRIs --remote-encoding=ENC use ENC as the default remote encoding --unlink remove file before clobber --keep...
首先,Shell 是一个程序,提供一个与用户对话的环境。这个环境只有一个命令提示符,让用户从键盘输入命令,所以又称为命令行环境(commandline,简写为 CLI)。Shell 接收到用户输入的命令,将命令送入操作系统执行,并将结果返回给用户。本书中,除非特别指明,Shell 指的就是命令行环境。 其次,Shell 是一个命令解释器,解释...
debug1:Sending command:scp-v-t/usr/local/redis/etc/bash:scp:command not founddebug1:client_input_channel_req:channel0rtype exit-status reply0debug1:client_input_channel_req:channel0rtype eow@openssh.com reply0debug1:channel0:free:client-session,nchannels1debug1:fd0clearingO_NONBLOCKdebug1:fd...
#POSIXforiin*.mp3;do[-e"$i"]||continuesome command"$i"done 如果你有使用引号[6]和避免单词拆分[7]的习惯,你完全可以避免很多错误。 注意下循环体内部的 "$i",这里会导致下面我们要说的另外一个比较容易犯的错误。 2. cp $file $target
if [ $? -eq 0 ]; then: Checks the exit status of the previous command. If it's 0 (indicating success), print a success message. Otherwise, it prints a failure message. 9. Write a Bash script that performs a simple arithmetic operation using user input. ...
prometheus_node_exporter.sh - starts Prometheus node_exporter locally, downloading it if not found in $PATH ssh_dump_stats.sh - uses SSH and dump_stats.sh to dump common command outputs from remote servers to a local tarball. Useful for vendor support cases ssh_dump_logs.sh - Uses SSH to...
shell C语言中Minibash，在execvp和父进程之间建立管道时出现问题如果父进程不通过管道与任何子进程通信，...
CommandDescription iconv Convert text file from one encoding to another. id Show user and group information for a specified user. if Execute a command conditionally. ifconfig Used to configure network interfaces. ifdown Stops a network interface. iftop It is a network analyzing tool used by ...
The exit status of the wait command is printed. $? is an internal Bash variable that holds the exit status of the last command executed. If you run the script, it will print something like this: PID: 36353 Exit status: 0 Here’s an example using the -n option: #!/bin/bash sleep ...