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安裝中文字典英文字典辭典工具!
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- bash - Shell equality operators (=, ==, -eq) - Stack Overflow
530 = and == are for string comparisons -eq is for numeric comparisons -eq is in the same family as -lt, -le, -gt, -ge, and -ne == is specific to bash (not present in sh (Bourne shell), ) Using POSIX = is preferred for compatibility In bash the two are equivalent, and in sh = is the only one that will work
- Whats the difference between lt; lt;, lt; lt; lt; and lt; lt; in bash?
What's the difference between <<, <<< and < < in bash?Here document << is known as here-document structure You let the program know what will be the ending text, and whenever that delimiter is seen, the program will read all the stuff you've given to the program as input and perform a task upon it Here's what I mean: $ wc << EOF > one two three > four five > EOF 2 5 24 In this example we
- An and operator for an if statement in Bash - Stack Overflow
Modern shells such as Bash and Zsh have inherited this construct from Ksh, but it is not part of the POSIX specification If you're in an environment where you have to be strictly POSIX compliant, stay away from it; otherwise, it's basically down to personal preference
- How to compare strings in Bash - Stack Overflow
How do I compare a variable to a string (and do something if they match)?
- shell - What does -ne mean in bash? - Stack Overflow
It doesn't mean anything "in bash" [ runs a command called test -ne is an argument to the test command, not to bash, and you can find its documentation in man test
- Whats the meaning of the parameter -e for bash shell command line?
123 I have as bash shell script with header #! bin bash -e When I run the script, it will be interrupted after the grep command runs, but when I remove the parameter -e, then the script can be run normally What is the meaning of parameter -e?
- sh - [: missing `] in bash script - Stack Overflow
The double-brace keyword is a bash expression, and will not work with other POSIX shells, but it has some benefits, as well, such as being able to do these kinds of operations more readably Of course, there are a lot of ways to test the number of arguments passed The mere existence of $2 will answer your question, as well
- How to increment a variable in bash? - Ask Ubuntu
#! bin bash # To focus exclusively on the performance of each type of increment # statement, we should exclude bash performing while loops from the # performance measure
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