公认的答案在典型情况下有效，但在边缘情况下无效，即：

对于没有扩展名的文件名（在这个答案的剩余部分中称为后缀），extension=${filename##*.}返回输入文件名，而不是空字符串。extension=${filename##*.}不包括首字母。，与惯例相反。盲目地准备。不适用于没有后缀的文件名。filename=“${filename%.*}”将是空字符串，如果输入文件名以开头。并且不包含进一步的。字符（例如.bash_profile）-与惯例相反。

---------

因此，覆盖所有边缘情况的鲁棒解决方案的复杂性需要一个函数——见下面的定义；它可以返回路径的所有组件。

示例调用：

splitPath '/etc/bash.bashrc' dir fname fnameroot suffix
# -> $dir == '/etc'
# -> $fname == 'bash.bashrc'
# -> $fnameroot == 'bash'
# -> $suffix == '.bashrc'

请注意，输入路径后面的参数是自由选择的位置变量名称。要跳过不感兴趣的变量，请指定_（使用扔掉变量$_）或“”；例如，要仅提取文件名根和扩展名，请使用splitPath“/etc/bash.bashrc”_ _ fnameroot扩展名。

# SYNOPSIS
#   splitPath path varDirname [varBasename [varBasenameRoot [varSuffix]]] 
# DESCRIPTION
#   Splits the specified input path into its components and returns them by assigning
#   them to variables with the specified *names*.
#   Specify '' or throw-away variable _ to skip earlier variables, if necessary.
#   The filename suffix, if any, always starts with '.' - only the *last*
#   '.'-prefixed token is reported as the suffix.
#   As with `dirname`, varDirname will report '.' (current dir) for input paths
#   that are mere filenames, and '/' for the root dir.
#   As with `dirname` and `basename`, a trailing '/' in the input path is ignored.
#   A '.' as the very first char. of a filename is NOT considered the beginning
#   of a filename suffix.
# EXAMPLE
#   splitPath '/home/jdoe/readme.txt' parentpath fname fnameroot suffix
#   echo "$parentpath" # -> '/home/jdoe'
#   echo "$fname" # -> 'readme.txt'
#   echo "$fnameroot" # -> 'readme'
#   echo "$suffix" # -> '.txt'
#   ---
#   splitPath '/home/jdoe/readme.txt' _ _ fnameroot
#   echo "$fnameroot" # -> 'readme'  
splitPath() {
  local _sp_dirname= _sp_basename= _sp_basename_root= _sp_suffix=
    # simple argument validation
  (( $# >= 2 )) || { echo "$FUNCNAME: ERROR: Specify an input path and at least 1 output variable name." >&2; exit 2; }
    # extract dirname (parent path) and basename (filename)
  _sp_dirname=$(dirname "$1")
  _sp_basename=$(basename "$1")
    # determine suffix, if any
  _sp_suffix=$([[ $_sp_basename = *.* ]] && printf %s ".${_sp_basename##*.}" || printf '')
    # determine basename root (filemane w/o suffix)
  if [[ "$_sp_basename" == "$_sp_suffix" ]]; then # does filename start with '.'?
      _sp_basename_root=$_sp_basename
      _sp_suffix=''
  else # strip suffix from filename
    _sp_basename_root=${_sp_basename%$_sp_suffix}
  fi
  # assign to output vars.
  [[ -n $2 ]] && printf -v "$2" "$_sp_dirname"
  [[ -n $3 ]] && printf -v "$3" "$_sp_basename"
  [[ -n $4 ]] && printf -v "$4" "$_sp_basename_root"
  [[ -n $5 ]] && printf -v "$5" "$_sp_suffix"
  return 0
}

test_paths=(
  '/etc/bash.bashrc'
  '/usr/bin/grep'
  '/Users/jdoe/.bash_profile'
  '/Library/Application Support/'
  'readme.new.txt'
)

for p in "${test_paths[@]}"; do
  echo ----- "$p"
  parentpath= fname= fnameroot= suffix=
  splitPath "$p" parentpath fname fnameroot suffix
  for n in parentpath fname fnameroot suffix; do
    echo "$n=${!n}"
  done
done

执行功能的测试代码：

test_paths=(
  '/etc/bash.bashrc'
  '/usr/bin/grep'
  '/Users/jdoe/.bash_profile'
  '/Library/Application Support/'
  'readme.new.txt'
)

for p in "${test_paths[@]}"; do
  echo ----- "$p"
  parentpath= fname= fnameroot= suffix=
  splitPath "$p" parentpath fname fnameroot suffix
  for n in parentpath fname fnameroot suffix; do
    echo "$n=${!n}"
  done
done

预期输出-注意边缘情况：

没有后缀的文件名以开头的文件名。（不考虑后缀的开头）以/结尾的输入路径（忽略尾随/）仅为文件名的输入路径（.作为父路径返回）超过的文件名-前缀标记（仅最后一个被视为后缀）：

----- /etc/bash.bashrc
parentpath=/etc
fname=bash.bashrc
fnameroot=bash
suffix=.bashrc
----- /usr/bin/grep
parentpath=/usr/bin
fname=grep
fnameroot=grep
suffix=
----- /Users/jdoe/.bash_profile
parentpath=/Users/jdoe
fname=.bash_profile
fnameroot=.bash_profile
suffix=
----- /Library/Application Support/
parentpath=/Library
fname=Application Support
fnameroot=Application Support
suffix=
----- readme.new.txt
parentpath=.
fname=readme.new.txt
fnameroot=readme.new
suffix=.txt

从Petersh答案构建，如果只需要文件名，路径和延伸都可以在单行中剥离，

filename=$(basename ${fullname%.*})

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

对于这个简单的任务，无需使用awk或sed，甚至perl。有一个纯Bash，os.path.splitext（）兼容的解决方案，它只使用参数扩展。

参考实施

os.path.splitext（路径）的文档：

将路径名路径拆分为一对（root、ext），使root+ext==路径，ext为空或以句点开头，最多包含一个句点。基名上的前导句点被忽略；splitext（'.cshrc'）返回（'.cshrc'，''）。

Python代码：

root, ext = os.path.splitext(path)

Bash实现

表彰领先时期

root="${path%.*}"
ext="${path#"$root"}"

忽略前导期

root="${path#.}";root="${path%"$root"}${root%.*}"
ext="${path#"$root"}"

测验

下面是忽略前导周期实现的测试用例，它应该与每个输入上的Python引用实现相匹配。

|---------------|-----------|-------|
|path           |root       |ext    |
|---------------|-----------|-------|
|' .txt'        |' '        |'.txt' |
|' .txt.txt'    |' .txt'    |'.txt' |
|' txt'         |' txt'     |''     |
|'*.txt.txt'    |'*.txt'    |'.txt' |
|'.cshrc'       |'.cshrc'   |''     |
|'.txt'         |'.txt'     |''     |
|'?.txt.txt'    |'?.txt'    |'.txt' |
|'\n.txt.txt'   |'\n.txt'   |'.txt' |
|'\t.txt.txt'   |'\t.txt'   |'.txt' |
|'a b.txt.txt'  |'a b.txt'  |'.txt' |
|'a*b.txt.txt'  |'a*b.txt'  |'.txt' |
|'a?b.txt.txt'  |'a?b.txt'  |'.txt' |
|'a\nb.txt.txt' |'a\nb.txt' |'.txt' |
|'a\tb.txt.txt' |'a\tb.txt' |'.txt' |
|'txt'          |'txt'      |''     |
|'txt.pdf'      |'txt'      |'.pdf' |
|'txt.tar.gz'   |'txt.tar'  |'.gz'  |
|'txt.txt'      |'txt'      |'.txt' |
|---------------|-----------|-------|

测试结果

所有测试均通过。

您还可以使用for循环和tr从路径中提取文件名。。。

for x in `echo $path | tr "/" " "`; do filename=$x; done

tr将路径中的所有“/”分隔符替换为空格，从而生成字符串列表，for循环扫描它们，最后一个在文件名变量中。

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