Bash throws error, line 8: $1: unbound variable, You are invoking your script with no arguments, so get_percent is being invoked with no arguments, causing $1 to be unset. Either check for this
unset -f/-v, ulimit -i/-m/-p/-q/-u/-x, type -a/-p/-t/-f/-P, suspend -f, kill -n, test -o optname/s1 == s2/s1 < s2/s1 > s2/-nt/-ot/-ef/-O/-G/-S bash reads ~/.bashrc for interactive shells, $ENV for non-interactive bash restricted shell mode is more extens...
unset a; a=1(echo "a is $a in the subshell")sh -c 'echo "a is $a in the child shell"' In the subshell, the regular shell variableais visible; but because it is not exported, the full child process does not see it. 上面的例子中把当前 Shell 执行外部命令 sh 启动的 Shell 叫做 ...
BashSupport Pro supports the unset command. unset allows you to make a variable unavailable to all following commands. The plugin considers variables, which have been unset as a new variable. a=1 echo $a # 'Go To Declaration' on a # navigates to a=1 # Rename will rename this a and pr...
$ 变量替换操作符 只有在变量被声明,赋值,unset或exported或者是在变量代表一个signal的时候, 变量才会是以本来的面目出现在脚本里.变量在被赋值的时候,可能需要使用"=", read状态或者是在循环的头部. 在""中还是会发生变量替换,这被叫做部分引用,或叫弱引用.而在''中就不会发生变...
${VAR:-STRING} If VAR is empty or unset, use STRING as its value. ${VAR-STRING} If VAR is unset, use STRING as its value. ${VAR:=STRING} If VAR is empty or unset, set the value of VAR to STRING. ${VAR=STRING} If VAR is unset, set the value of VAR to STRING. ${VAR:...
Documentation of a Bash variable All previous modifications of type and properties are tracked. It stops when there’s no more declaration or until the firstunset. Line comments, which immediately precede the first declaration, are displayed as documentation of that variable. The scope of the varia...
Once a variable is set, it may be unset only by using the unset builtin command (see GNU Bash-4.1 Last change: 2009 December 29 13 User Commands BASH(1) SHELL BUILTIN COMMANDS below). A variable may be assigned to by a statement of the form name=[value] If value is not given, ...
Fish sets and erases variables withsetinstead ofVAR=VALand a variety of separate builtins likedeclareandunsetandexport.settakes options to determine the scope and exportedness of a variable: # Define $PAGER *g*lobal and e*x*ported,# so this is like ``export PAGER=less``set-gx PAGER less...
unset -f/-v, ulimit -i/-m/-p/-q/-u/-x, type -a/-p/-t/-f/-P, suspend -f, kill -n, test -o optname/s1 == s2/s1 < s2/s1 > s2/-nt/-ot/-ef/-O/-G/-S bash reads ~/.bashrc for interactive shells, $ENV for non-interactive ...