$ ./checkarg'''./checkarg: line5:1: A non-empty argument is required $ ./checkarg x''./checkarg: line5:2: Two non-empty arguments are required $ ./checkarg x x Thank you. (5) ${#var}: 变量内容的长度 readpasswdif[ ${#passwd} -lt8]thenprintf"Password is too short: %d c...
清单5-2。checkarg,如果参数未设置或为空,退出 ## Check for unset arguments : ${1?An argument is required} \ ${2?Two arguments are required} ## Check for empty arguments : ${1:?A non-empty argument is required} \ ${2:?Two non-empty arguments are required} echo "Thank you." 第...
1.echo 命令格式:echo arg 功能:在屏幕上显示出由arg指定的字串。 2.eval 命令格式:eval args 功能:当Shell程序执行到eval语句时,Shell读入参数args,并将它们组合成一个新的命令,然后执行。 3.exec 命令格式:exec命令参数 功能:当Shell执行到exec语句时,不会去创建新的子进程,而是转去执行指定的命令,当指定的...
echo "opt_f is $opt_f" echo "opt_l is $opt_l" echo "first arg is $1" echo "2nd arg is $2" 您可以这样运行该脚本: cmdparser -l hello -f -- -somefile1 somefile2 返回的结果是: opt_f is 1 opt_l is hello first arg is -somefile1 2nd arg is somefile2 1. 2. 3. 4....
"${@}"if ((flag_option_flag)); then echo "flag option set"fiif ((abc_option_flag)); then # Check if the flag options are set or ON: # Logic for when --abc is set. # "${abc_arg}" should also be set. echo "Using --abc option -> arg: [${abc_arg}]"fi...
command [-pVv] command [arg ...] 運行 command ,使用 args 作為參數,禁止通常的查找 shell 函數的過程。只有內建命令或者 PATH 中包含的 命令可以執行。如果給出 -p 參數, command 的查找是以 PATH 的預設值進行的。這樣可以保証找到所有的標 準工具。如果給出 -V 或者-v 選項,關於 command 的說明將被...
command [-pVv] command [arg ...] 運行 command ,使用 args 作爲參數,禁止通常的查找 shell 函數的過程。只有內建命令或者 PATH 中包含的 命令可以執行。如果給出 -p 參數, command 的查找是以 PATH 的默認值進行的。這樣可以保證找到所有的標 準工具。如果給出 -V 或者-v 選項,關於 command 的說明將被...
./my_script.sh arg1 arg2 Inside the script, you can use $1 for the 1st argument, $2 for the 2nd argument and so on. $0 is a special variable that holds the name of the script being executed. Now, create a new shell script namedarguments.shand add the following lines to it: ...
How to check if a command succeeds or failed? How to do string comparison and check if a string equals to a value? How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not ...
-l Make bash act as if it had been invoked as a login shell (see INVOCATION below). -r If the -r option is present, the shell becomes restricted (see RESTRICTED SHELL below). -s If the -s option is present, or if no arguments remain after option processing, then commands are read...