string KSH 检查字符串是否以子字符串开头
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KSH check if string starts with substring
提问by z4y4ts
I need to check if the variable has value of string which starts with specified substring.
我需要检查变量是否具有以指定子字符串开头的字符串值。
In Python it would be something like this:
在 Python 中，它会是这样的：
foo = 'abcdef'
if foo.startswith('abc'):
print 'Success'
What is the most explicit way to check in Ksh whether strig $foostarts with substring bar?
在 Ksh 中检查 srig 是否$foo以 substring 开头的最明确的方法是什么bar？
回答by Aaron Digulla
It's very simple but looks a bit odd:
这很简单，但看起来有点奇怪：
if [[ "$foo" == abc* ]]; then ...
One would assume that ksh would expand the pattern with the files in the current directory but instead, it does pattern matching. You need the [[, though. Single [won't work. The quotes are not strictly necessary if there are no blanks in foo.
人们会假设 ksh 将使用当前目录中的文件扩展模式，但相反，它进行模式匹配。但是，您需要[[。单身[不行。如果foo.
回答by glenn Hymanman
Also:
还：
foo='abcdef'
pattern='abc*'
case "$foo" in
$pattern) echo startswith ;;
*) echo otherwise ;;
esac
回答by Paused until further notice.
You can also do regex matching:
您还可以进行正则表达式匹配：
if [[ $foo =~ ^abc ]]
For more complex patterns, I recommend using a variable instead of putting the pattern directly in the test:
对于更复杂的模式，我建议使用变量而不是将模式直接放在测试中：
bar='^begin (abc|def|ghi)[^ ]* end$'
if [[ $foo =~ $bar ]]
