通常您已经知道扩展名，因此您可能希望使用：

basename filename .extension

例如：

basename /path/to/dir/filename.txt .txt

我们得到

filename

~% 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。

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。

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  = ""

我认为，如果您只需要文件名，可以尝试以下操作：

FULLPATH=/usr/share/X11/xorg.conf.d/50-synaptics.conf

# Remove all the prefix until the "/" character
FILENAME=${FULLPATH##*/}

# Remove all the prefix until the "." character
FILEEXTENSION=${FILENAME##*.}

# Remove a suffix, in our case, the filename. This will return the name of the directory that contains this file.
BASEDIRECTORY=${FULLPATH%$FILENAME}

echo "path = $FULLPATH"
echo "file name = $FILENAME"
echo "file extension = $FILEEXTENSION"
echo "base directory = $BASEDIRECTORY"

这就是全部=D。