/bin/bash#Ping & get DNS name from a list of IPs saved in a file#Prompt the user to enter a file name and its path.read-p"Enter the IP addresses file name / path:"FILE_PATH_NAME (continued)functioncheck_host(){#if not the IP address value is emptyif[[ -n$IP_ADDRESS]]thenpin...
$ VAR_NAME='value'# 变量赋值, 注意等号两边不能有空格$echo"I am$VAR_NAME,${VAR_NAME}"# 通过$符使用变量$ $ LIST=$(ls)# 将shell命令结果赋值给变量,$ SERVER_NAME=$(hastname)# 参考子命令扩展 全局变量:在脚本中任何位置都可以使用该变量,shell变量默认都是全局变量。
$variable 是要检查的变量。 pattern1, pattern2 等是匹配模式。 commands1, commands2 等是匹配成功后要执行的命令。 * 是通配符,用于匹配所有未被前面的模式捕获的情况。 esac 是case 的结束标记。 优势 可读性:相比于多个 if-else 语句,case 语句更加直观和易于阅读。 简洁性:减少了代码的冗余,使得脚本更加...
"$BASH_ENV"; fi but the value of the PATH variable is not used to search for the file name. If bash is invoked with the name sh, it tries to mimic the startup behavior of historical versions of sh as closely as possible, while conforming to the POSIX standard as well. When invoked...
value1) command(s) ;; value2) command(s) ;; ……… *) command(s) ;; esac 4、循环语句 4.1、for循环 格式: for variable in word_list do command(s) done 写成一行: for var in item1 item2 ... itemN; do command1; command2… done; C风格的...
${variable:pos}: 偏移pos个字符,取余下的子串 name=jerry,name:2结果为rryname:2结果为rry{variable:pos:num}: 偏移pos个字符,取num个字符长度的子串 name=‘hello world’, ${name:2:5}结果为“llo w” 字符串处理,将来在bash中经常用的
regex`trap'exit 42'sigint# Unportable signal speccmd &> file# Unportable redirection operatorreadfoo < /dev/tcp/host/22# Unportable intercepted filesfoo-bar() { ..; }# Undefined/unsupported function name[$UID= 0 ]# Variable undefined in dash/shlocalvar=value# local is undefined in shtim...
If the environment variable $XDG_CONFIG_HOME is present, it will place the nvm files there. You can add --no-use to the end of the above script to postpone using nvm until you manually use it:export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" ||...
aws_secret_add.sh - reads a value from a command line argument or non-echo prompt and saves it to Secrets Manager. Useful for uploading a password without exposing it on your screen aws_secret_add_binary.sh - base64 encodes a given file's contents and saves it to Secrets Manager as a...
terminates on a fatal signal N, bash uses the value of 128+N as the exit status. As usual, you should always read the man page of the scripts you're calling, to see what the conventions are for each of them. If you've programmed with a language like Java or Python, then you're...