如果文件没有扩展名或文件名，这似乎不起作用。这是我正在使用的；它只使用内置文件名，并处理更多（但不是所有）病态文件名。

#!/bin/bash
for fullpath in "$@"
do
    filename="${fullpath##*/}"                      # Strip longest match of */ from start
    dir="${fullpath:0:${#fullpath} - ${#filename}}" # Substring from 0 thru pos of filename
    base="${filename%.[^.]*}"                       # Strip shortest match of . plus at least one non-dot char from end
    ext="${filename:${#base} + 1}"                  # Substring from len of base thru end
    if [[ -z "$base" && -n "$ext" ]]; then          # If we have an extension and no base, it's really the base
        base=".$ext"
        ext=""
    fi

    echo -e "$fullpath:\n\tdir  = \"$dir\"\n\tbase = \"$base\"\n\text  = \"$ext\""
done

下面是一些测试用例：

$ basename-and-extension.sh / /home/me/ /home/me/file /home/me/file.tar /home/me/file.tar.gz /home/me/.hidden /home/me/.hidden.tar /home/me/.. .
/:
    dir  = "/"
    base = ""
    ext  = ""
/home/me/:
    dir  = "/home/me/"
    base = ""
    ext  = ""
/home/me/file:
    dir  = "/home/me/"
    base = "file"
    ext  = ""
/home/me/file.tar:
    dir  = "/home/me/"
    base = "file"
    ext  = "tar"
/home/me/file.tar.gz:
    dir  = "/home/me/"
    base = "file.tar"
    ext  = "gz"
/home/me/.hidden:
    dir  = "/home/me/"
    base = ".hidden"
    ext  = ""
/home/me/.hidden.tar:
    dir  = "/home/me/"
    base = ".hidden"
    ext  = "tar"
/home/me/..:
    dir  = "/home/me/"
    base = ".."
    ext  = ""
.:
    dir  = ""
    base = "."
    ext  = ""

~% FILE="example.tar.gz"

~% echo "${FILE%%.*}"
example

~% echo "${FILE%.*}"
example.tar

~% echo "${FILE#*.}"
tar.gz

~% echo "${FILE##*.}"
gz

有关详细信息，请参阅Bash手册中的shell参数扩展。

这是我在编写Bash脚本时用于查找文件名和扩展名的算法，当名称与大小写冲突时，该脚本会使名称唯一。

#! /bin/bash 

#
# Finds 
# -- name and extension pairs
# -- null extension when there isn't an extension.
# -- Finds name of a hidden file without an extension
# 

declare -a fileNames=(
  '.Montreal' 
  '.Rome.txt' 
  'Loundon.txt' 
  'Paris' 
  'San Diego.txt'
  'San Francisco' 
  )

echo "Script ${0} finding name and extension pairs."
echo 

for theFileName in "${fileNames[@]}"
do
     echo "theFileName=${theFileName}"  

     # Get the proposed name by chopping off the extension
     name="${theFileName%.*}"

     # get extension.  Set to null when there isn't an extension
     # Thanks to mklement0 in a comment above.
     extension=$([[ "$theFileName" == *.* ]] && echo ".${theFileName##*.}" || echo '')

     # a hidden file without extenson?
     if [ "${theFileName}" = "${extension}" ] ; then
         # hidden file without extension.  Fixup.
         name=${theFileName}
         extension=""
     fi

     echo "  name=${name}"
     echo "  extension=${extension}"
done 

测试运行。

$ config/Name\&Extension.bash 
Script config/Name&Extension.bash finding name and extension pairs.

theFileName=.Montreal
  name=.Montreal
  extension=
theFileName=.Rome.txt
  name=.Rome
  extension=.txt
theFileName=Loundon.txt
  name=Loundon
  extension=.txt
theFileName=Paris
  name=Paris
  extension=
theFileName=San Diego.txt
  name=San Diego
  extension=.txt
theFileName=San Francisco
  name=San Francisco
  extension=
$ 

仅供参考：完整的音译程序和更多测试用例可以在这里找到：https://www.dropbox.com/s/4c6m0f2e28a1vxf/avoid-clashes-code.zip?dl=0

首先，获取不带路径的文件名：

filename=$(basename -- "$fullfile")
extension="${filename##*.}"
filename="${filename%.*}"

或者，您可以关注路径的最后一个“/”，而不是“.”即使您有不可预知的文件扩展名，也可以使用：

filename="${fullfile##*/}"

您可能需要检查文档：

在网页“3.5.3外壳参数扩展”部分在bash手册页的“参数扩展”部分

Mellen在一篇博客文章中写道：

使用Bash，还有${file%.*}获取不带扩展名的文件名，${file##*.}单独获取扩展名。即，

file="thisfile.txt"
echo "filename: ${file%.*}"
echo "extension: ${file##*.}"

输出：

filename: thisfile
extension: txt

这里是一个sed解决方案，它以各种形式提取路径组件，并可以处理大多数边缘情况：

## Enter the input path and field separator character, for example:
## (separatorChar must not be present in inputPath)

inputPath="/path/to/Foo.bar"
separatorChar=":"

## sed extracts the path components and assigns them to output variables

oldIFS="$IFS"
IFS="$separatorChar"
read dirPathWithSlash dirPath fileNameWithExt fileName fileExtWithDot fileExt <<<"$(sed -En '
s/^[[:space:]]+//
s/[[:space:]]+$//
t l1
:l1
s/^([^/]|$)//
t
s/[/]+$//
t l2
:l2
s/^$/filesystem\/\
filesystem/p
t
h
s/^(.*)([/])([^/]+)$/\1\2\
\1\
\3/p
g
t l3
:l3
s/^.*[/]([^/]+)([.])([a-zA-Z0-9]+)$/\1\
\2\3\
\3/p
t
s/^.*[/](.+)$/\1/p
' <<<"$inputPath" | tr "\n" "$separatorChar")"
IFS="$oldIFS"

## Results (all use separatorChar=":")

## inputPath        = /path/to/Foo.bar
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = Foo.bar
## fileName         = Foo
## fileExtWithDot   = .bar
## fileExt          = bar

## inputPath        = /path/to/Foobar
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = Foobar
## fileName         = Foobar
## fileExtWithDot   =
## fileExt          =

## inputPath        = /path/to/...bar
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = ...bar
## fileName         = ..
## fileExtWithDot   = .bar
## fileExt          = bar

## inputPath        = /path/to/..bar
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = ..bar
## fileName         = .
## fileExtWithDot   = .bar
## fileExt          = bar

## inputPath        = /path/to/.bar
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = .bar
## fileName         = .bar
## fileExtWithDot   = 
## fileExt          = 

## inputPath        = /path/to/...
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = ...
## fileName         = ...
## fileExtWithDot   =
## fileExt          =

## inputPath        = /path/to/Foo.
## dirPathWithSlash = /path/to/
## dirPath          = /path/to 
## fileNameWithExt  = Foo.
## fileName         = Foo.
## fileExtWithDot   =
## fileExt          =

## inputPath        = / (the root directory)
## dirPathWithSlash = filesystem/
## dirPath          = filesystem
## fileNameWithExt  =
## fileName         =
## fileExtWithDot   =
## fileExt          =

## inputPath        =  (invalid because empty)
## dirPathWithSlash =
## dirPath          =
## fileNameWithExt  =
## fileName         =
## fileExtWithDot   =
## fileExt          =

## inputPath        = Foo/bar (invalid because doesn't start with a forward slash)
## dirPathWithSlash =
## dirPath          =
## fileNameWithExt  =
## fileName         =
## fileExtWithDot   =
## fileExt          =

以下是它的工作原理：

sed解析输入路径，并在单独的行上按顺序打印以下路径组件：

带有尾随斜杠字符的目录路径没有尾随斜杠字符的目录路径带扩展名的文件名不带扩展名的文件名带前导点字符的文件扩展名不带前导点字符的文件扩展名

tr将sed输出转换为上述路径组件的分隔符分隔字符串。

read使用分隔符作为字段分隔符（IFS=“$sseparatorChar”），并将每个路径组件分配给各自的变量。

以下是sed构造的工作原理：

s/^[[：space:]]+/-和s/[[：space：]]+$//去掉任何前导和/或尾随空格字符t l1和：l1为下一个s函数刷新t函数s/^（[^/]|$）//和t测试输入路径是否无效（不是以正斜杠开头的路径），在这种情况下，它将所有输出行留空并退出sed命令s/[/]+$//去掉任何尾随斜线t l2和：l2为下一个s函数刷新t函数s/^$/files\/\\[newline]filesystem/p和t测试输入路径由根目录/组成的特殊情况，在这种情况下，它为dirPathWithSlash和dirPath输出行打印文件系统/和文件系统，将所有其他输出行留空，并退出sed命令h将输入路径保存在等待空间中s/^（.*）（[/]）（[^/]+）$/\1\\2\\[newline]\1\\[newline]\3/p打印dirPathWithSlash、dirPath和fileNameWithExt输出行g从保持空间检索输入路径t l3和：l3为下一个s函数刷新t函数s/^.*\[/]（[^/]+）（[.]）（[a-zA-Z0-9]+）$/\1\\[newline]\2\3\[newline]\3/p，并在存在文件扩展名的情况下打印fileName、fileExtWithDot和fileExt输出行（假设仅由字母数字字符组成），然后退出sed命令s/^.*\[/]（.+）$/\1/p在文件扩展名不存在的情况下打印fileName，但不打印fileExtWithDot和fileExt输出行，然后退出sed命令。