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This article shows you what the variable parameter $means in Linux. The content is concise and easy to understand. It will definitely make your eyes shine. I hope you can gain something through the detailed introduction of this article.

Meaning of Linux variable parameter $

Let's write a simple script first and explain the meaning of each variable after execution # touch variable# vi variable The script reads as follows: #!/ bin/shecho "number：$#"

echo "scname：$0"

echo "first ：$1"

echo "second：$2"

echo "argume：$@"

echo "show parm list：$*"

echo "show process id：$$"

echo "show precomm stat： $？"

Save Exit Grant Script Execution Permission # chmod +x variable Execute Script #./ variable aa bbnumber:2

scname：。/ variable

first:aa

second:bb

argume:aa bbshow parm list:aa bb

show process id:24544show precomm stat:0

As you can see from the display: $#is the number of parameters passed to the script $0 is the name of the script $1 is the first parameter passed to the shell script $2 is the second parameter passed to the shell script $@ is a list of all parameters passed to the script $* is a single string showing all parameters passed to the script, unlike the positional variable, which can have more than 9 parameters $is the ID number of the current process the script runs $? Yes Displays the exit status of the last command, 0 indicates no errors, others indicate errors

What does the variable parameter $mean in Linux? Have you learned any knowledge or skills? If you want to learn more skills or enrich your knowledge reserves, please pay attention to the industry information channel.

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