我在Bash中有一个字符串：
string="My string"
如何测试它是否包含另一个字符串？
if [ $string ?? 'foo' ]; then
echo "It's there!"
fi
哪里是我不认识的接线员。我使用echo和grep吗？
if echo "$string" | grep 'foo'; then
echo "It's there!"
fi
这看起来有点笨拙。
当前回答
一个是：
[ $(expr $mystring : ".*${search}.*") -ne 0 ] && echo 'yes' || echo 'no'
其他回答
这里回答的问题的扩展如何判断POSIX sh中的字符串是否包含另一个字符串？：
此解决方案适用于特殊字符：
# contains(string, substring)
#
# Returns 0 if the specified string contains the specified substring,
# otherwise returns 1.
contains() {
string="$1"
substring="$2"
if echo "$string" | $(type -p ggrep grep | head -1) -F -- "$substring" >/dev/null; then
return 0 # $substring is in $string
else
return 1 # $substring is not in $string
fi
}
contains "abcd" "e" || echo "abcd does not contain e"
contains "abcd" "ab" && echo "abcd contains ab"
contains "abcd" "bc" && echo "abcd contains bc"
contains "abcd" "cd" && echo "abcd contains cd"
contains "abcd" "abcd" && echo "abcd contains abcd"
contains "" "" && echo "empty string contains empty string"
contains "a" "" && echo "a contains empty string"
contains "" "a" || echo "empty string does not contain a"
contains "abcd efgh" "cd ef" && echo "abcd efgh contains cd ef"
contains "abcd efgh" " " && echo "abcd efgh contains a space"
contains "abcd [efg] hij" "[efg]" && echo "abcd [efg] hij contains [efg]"
contains "abcd [efg] hij" "[effg]" || echo "abcd [efg] hij does not contain [effg]"
contains "abcd *efg* hij" "*efg*" && echo "abcd *efg* hij contains *efg*"
contains "abcd *efg* hij" "d *efg* h" && echo "abcd *efg* hij contains d *efg* h"
contains "abcd *efg* hij" "*effg*" || echo "abcd *efg* hij does not contain *effg*"
我发现我经常需要这个功能，所以我在.bashrc中使用了一个自制的shell函数，这样我就可以随时重用它，并使用一个容易记住的名字：
function stringinstring()
{
case "$2" in
*"$1"*)
return 0
;;
esac
return 1
}
要测试$string1（例如，abc）是否包含在$string2（例如，123abcABC）中，我只需要运行striginstring“$string1”“$string2”并检查返回值，例如
stringinstring "$str1" "$str2" && echo YES || echo NO
如果您喜欢正则表达式方法：
string='My string';
if [[ $string =~ "My" ]]; then
echo "It's there!"
fi
我不确定是否使用if语句，但您可以使用case语句获得类似的效果：
case "$string" in
*foo*)
# Do stuff
;;
esac
[[ $string == *foo* ]] && echo "It's there" || echo "Couldn't find"
