在Bash中,测试数组是否包含某个值的最简单方法是什么?
当前回答
这对我来说很管用:
# traditional system call return values-- used in an `if`, this will be true when returning 0. Very Odd.
contains () {
# odd syntax here for passing array parameters: http://stackoverflow.com/questions/8082947/how-to-pass-an-array-to-a-bash-function
local list=$1[@]
local elem=$2
# echo "list" ${!list}
# echo "elem" $elem
for i in "${!list}"
do
# echo "Checking to see if" "$i" "is the same as" "${elem}"
if [ "$i" == "${elem}" ] ; then
# echo "$i" "was the same as" "${elem}"
return 0
fi
done
# echo "Could not find element"
return 1
}
示例调用:
arr=("abc" "xyz" "123")
if contains arr "abcx"; then
echo "Yes"
else
echo "No"
fi
其他回答
下面是实现这一点的一个小函数。搜索字符串是第一个参数,其余是数组元素:
set +e #otherwise the script will exit on error
containsElement () {
local e match="$1"
shift
for e; do [[ "$e" == "$match" ]] && return 0; done
return 1
}
该函数的测试运行如下:
$ array=("something to search for" "a string" "test2000")
$ containsElement "a string" "${array[@]}"
$ echo $?
0
$ containsElement "blaha" "${array[@]}"
$ echo $?
1
for i in "${array[@]}"
do
if [ "$i" -eq "$yourValue" ] ; then
echo "Found"
fi
done
字符串:
for i in "${array[@]}"
do
if [ "$i" == "$yourValue" ] ; then
echo "Found"
fi
done
@ghostdog74关于使用大小写逻辑检查数组包含特定值的回答的一个小补充:
myarray=(one two three)
word=two
case "${myarray[@]}" in ("$word "*|*" $word "*|*" $word") echo "found" ;; esac
或者打开extglob选项,你可以这样做:
myarray=(one two three)
word=two
shopt -s extglob
case "${myarray[@]}" in ?(*" ")"$word"?(" "*)) echo "found" ;; esac
我们也可以用if语句:
myarray=(one two three)
word=two
if [[ $(printf "_[%s]_" "${myarray[@]}") =~ .*_\[$word\]_.* ]]; then echo "found"; fi
containsElement () { for e in "${@:2}"; do [[ "$e" = "$1" ]] && return 0; done; return 1; }
现在正确处理空数组。
有点晚了,但你可以用这个:
#!/bin/bash
# isPicture.sh
FILE=$1
FNAME=$(basename "$FILE") # Filename, without directory
EXT="${FNAME##*.}" # Extension
FORMATS=(jpeg JPEG jpg JPG png PNG gif GIF svg SVG tiff TIFF)
NOEXT=( ${FORMATS[@]/$EXT} ) # Formats without the extension of the input file
# If it is a valid extension, then it should be removed from ${NOEXT},
#+making the lengths inequal.
if ! [ ${#NOEXT[@]} != ${#FORMATS[@]} ]; then
echo "The extension '"$EXT"' is not a valid image extension."
exit
fi