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

~% 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。

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

我使用以下脚本

$ echo "foo.tar.gz"|rev|cut -d"." -f3-|rev
foo

这里有一些替代建议（主要是awk），包括一些高级用例，比如提取软件包的版本号。

请注意，如果输入稍有不同，其中一些可能会失败，因此任何使用这些输入的人都应验证其预期输入，并根据需要调整正则表达式。

f='/path/to/complex/file.1.0.1.tar.gz'

# Filename : 'file.1.0.x.tar.gz'
    echo "$f" | awk -F'/' '{print $NF}'

# Extension (last): 'gz'
    echo "$f" | awk -F'[.]' '{print $NF}'
    
# Extension (all) : '1.0.1.tar.gz'
    echo "$f" | awk '{sub(/[^.]*[.]/, "", $0)} 1'
    
# Extension (last-2): 'tar.gz'
    echo "$f" | awk -F'[.]' '{print $(NF-1)"."$NF}'

# Basename : 'file'
    echo "$f" | awk '{gsub(/.*[/]|[.].*/, "", $0)} 1'

# Basename-extended : 'file.1.0.1.tar'
    echo "$f" | awk '{gsub(/.*[/]|[.]{1}[^.]+$/, "", $0)} 1'

# Path : '/path/to/complex/'
    echo "$f" | awk '{match($0, /.*[/]/, a); print a[0]}'
    # or 
    echo "$f" | grep -Eo '.*[/]'
    
# Folder (containing the file) : 'complex'
    echo "$f" | awk -F'/' '{$1=""; print $(NF-1)}'
    
# Version : '1.0.1'
    # Defined as 'number.number' or 'number.number.number'
    echo "$f" | grep -Eo '[0-9]+[.]+[0-9]+[.]?[0-9]?'

    # Version - major : '1'
    echo "$f" | grep -Eo '[0-9]+[.]+[0-9]+[.]?[0-9]?' | cut -d. -f1

    # Version - minor : '0'
    echo "$f" | grep -Eo '[0-9]+[.]+[0-9]+[.]?[0-9]?' | cut -d. -f2

    # Version - patch : '1'
    echo "$f" | grep -Eo '[0-9]+[.]+[0-9]+[.]?[0-9]?' | cut -d. -f3

# All Components : "path to complex file 1 0 1 tar gz"
    echo "$f" | awk -F'[/.]' '{$1=""; print $0}'
    
# Is absolute : True (exit-code : 0)
    # Return true if it is an absolute path (starting with '/' or '~/'
    echo "$f" | grep -q '^[/]\|^~/'
 

所有用例都使用原始完整路径作为输入，而不依赖中间结果。

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