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