/bin/bash # Calculate the week number using the date command: WEEKOFFSET=$[ $(date +"%V") % 2 ] # Test if we have a remainder. If not, this is an even week so send a message. # Else, do nothing. if [ $WEEKOFFSET -eq "0" ]; then echo "Sunday evening, put out the gar...
if grep 'bash$' /etc/passwd &>/dev/null; then echo "There is `grep 'bash$' /etc/passwd|wc -l|cut -d' ' -f1` users use bash." else echo " There is none user use the bash." fi #!/bin/bash FILE=/ect/inittab if [ ! -e $FILE ]; then echo "NO $FILE." exit 8 fi ...
if 语句可以嵌套使用。看如下 weather.sh 脚本: 登录后复制#!/bin/bashTEMP=$1if[$TEMP-gt 5 ];thenif[$TEMP-lt 15 ];thenecho"The weather is cold."elif[$TEMP-lt 25 ];thenecho"The weather is nice."elseecho"The weather is hot."fielseecho"It's freezing outside ..."fi 上述脚本接受温...
问由于超时而关闭bash时运行命令。EN版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。
我们还可以在 bash 中使用case语句来替换多个 if 语句,其构造的一般语法如下: 复制 case"variable"in"pattern1"Command … ;;"pattern2"Command … ;;"pattern2"Command … ;;esac 1. 注意: 条件语句最后总会包含一个空格和右括号); 条件语句后的命令以两个分号;;结束,其前面的空格可有可没有; ...
,格式跟着标准走if(WEXITSTATUS(status)==168)printf("%s: Error - %s\n",argv[0],"The directive is not yet defined");}else//如果子进程被异常终止,打印相关信息printf("process run fail! [code_dump]:%d [exit_signal]:%d\n",(status>>7)&1,status&0x7F);//子进程异常终止的情况}return0;...
some 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 $target 上面的命令有什么问题呢?如果你提前知道,$file 和 $target 文件名中不会包含空格或者*号。否则,这行命...
我们需要注意shell中的返回和在其他程序,例如C语言中的返回是不一样的,只代表最后的exit statue,而不是所谓的返回值,虽然也用到了return。如何没有最后的reture,例如后面的push_func,exit status就是最后执行的command的exit status return $result } push_func( )...
Exit status 127 tells you that one of two things has happened: Either the command doesn't exist, or the command isn't in your path ($PATH). This code also appears if you attempt to execute a command that is in your current working directory. For example, the script above that you ga...
Did you know that every command you run in Linux has an exit code? This is true even if a command terminates with an error. Exit values are integer values that range from 0 to 255. A non-zero value, i.e., a value higher than 0, indicates the command exits with an error. ...