通常，在cshrc文件中包含以下内容以设置路径：

set path = ( . $otherpath $path )

但是，当我们多次获取cshrc文件时，路径会重复，那么如何防止重复？

编辑：这是一种不干净的方法：

set localpaths = ( . $otherpaths )
echo ${path} | egrep -i "$localpaths" >& /dev/null
if ($status != 0) then
    set path = ( . $otherpaths $path )
endif

解决方案

我总是在.cshrc中设置从头开始的路径。
那是我从一条基本路径开始的，就像：

set path = (. ~/bin /bin /usr/bin /usr/ucb /usr/bin/X11)

(取决于系统)。

然后执行：

set path = ($otherPath $path)

添加更多的东西

我们可以使用以下Perl脚本来修剪重复项的路径。

#!/usr/bin/perl
#
# ^^ ensure this is pointing to the correct location.
#
# Title:    SLimPath
# Author:   David "Shoe Lace" Pyke <[email protected] >
#   :   Tim Nelson 
# Purpose: To create a slim version of my envirnoment path so as to eliminate
#       duplicate entries and ensure that the "." path was last.
# Date Created: April 1st 1999
# Revision History:
#   01/04/99: initial tests.. didn't wok verywell at all
#       : retreived path throught '$ENV' call
#   07/04/99: After an email from Tim Nelson <[email protected]> got it to
#         work.
#       : used 'push' to add to array
#       : used 'join' to create a delimited string from a list/array.
#   16/02/00: fixed cmd-line options to look/work better
#   25/02/00: made verbosity level-oriented
#
#

use Getopt::Std;

sub printlevel;

$initial_str = "";
$debug_mode = "";
$delim_chr = ":";
$opt_v = 1;

getopts("v:hd:l:e:s:");

OPTS: {
    $opt_h && do {
print "\n
case $PATH in
    *:$HOME/bin | *:$HOME/bin:* ) ;;
    *) export PATH=$PATH:$HOME/bin
esac
 [-v level] [-d level] [-l delim] ( -e varname | -s strname | -h )";
print "\nWhere:";
print "\n   -h  This help";
print "\n   -d  Debug level";
print "\n   -l  Delimiter (between path vars)";
print "\n   -e  Specify environment variable (NB: don't include $ sign)";
print "\n   -s  String (ie. 
:   "@(#)$Id: clnpath.sh,v 1.6 1999/06/08 23:34:07 jleffler Exp $"
#
#   Print minimal version of $PATH, possibly removing some items

case $# in
0)  chop=""; path=${PATH:?};;
1)  chop=""; path=;;
2)  chop=; path=;;
*)  echo "Usage: `basename 
export PATH=$(clnpath /new/bin:/other/bin:$PATH /old/bin:/extra/bin)
 .sh` [$PATH [remove:list]]" >&2
    exit 1;;
esac

# Beware of the quotes in the assignment to chop!
echo "$path" |
${AWK:-awk} -F: '#
BEGIN   {   # Sort out which path components to omit
            chop="'"$chop"'";
            if (chop != "") nr = split(chop, remove); else nr = 0;
            for (i = 1; i <= nr; i++)
                omit[remove[i]] = 1;
        }
{
    for (i = 1; i <= NF; i++)
    {
        x=$i;
        if (x == "") x = ".";
        if (omit[x] == 0 && path[x]++ == 0)
        {
            output = output pad x;
            pad = ":";
        }
    }
    print output;
}'
 -s $PATH:/looser/bin/)";
print "\n   -v  Verbosity (0 = quiet, 1 = normal, 2 = verbose)";
print "\n";
        exit;
    };
    $opt_d && do {
        printlevel 1, "You selected debug level $opt_d\n";
        $debug_mode = $opt_d;
    };
    $opt_l && do {
        printlevel 1, "You are going to delimit the string with \"$opt_l\"\n";
        $delim_chr = $opt_l;
    };
    $opt_e && do {
        if($opt_s) { die "Cannot specify BOTH env var and string\n"; }
        printlevel 1, "Using Environment variable \"$opt_e\"\n";
        $initial_str = $ENV{$opt_e};
    };
    $opt_s && do {
        printlevel 1, "Using String \"$opt_s\"\n";
        $initial_str = $opt_s;
    };
}

if( ($#ARGV != 1) and !$opt_e and !$opt_s){
    die "Nothing to work with -- try 
set path=(`echo $path | tr ' ' '\n' | sort | uniq | tr '\n' ' '`)
 -h\n";
}

$what = shift @ARGV;
# Split path using the delimiter
@dirs = split(/$delim_chr/, $initial_str);

$dest;
@newpath = ();
LOOP: foreach (@dirs){
    # Ensure the directory exists and is a directory
    if(! -e ) { printlevel 1, "$_ does not exist\n"; next; }
    # If the directory is ., set $dot and go around again
    if($_ eq '.') { $dot = 1; next; }

#   if ($_ ne `realpath $_`){
#           printlevel 2, "$_ becomes ".`realpath $_`."\n";
#   }
    undef $dest;
    #$_=Stdlib::realpath($_,$dest);
    # Check for duplicates and dot path
    foreach $adir (@newpath) { if($_ eq $adir) { 
        printlevel 2, "Duplicate: $_\n";
        next LOOP; 
    }}

    push @newpath, $_;
}

# Join creates a string from a list/array delimited by the first expression
print join($delim_chr, @newpath) . ($dot ? $delim_chr.".\n" : "\n");

printlevel 1, "Thank you for using 
foreach dir ( $localdirs )
    echo ${path} | egrep -i "$dir" >& /dev/null
    if ($status != 0) then
        set path = ( $dir $path )
    endif
end
\n";
exit;

sub printlevel {
    my($level, $string) = @_;

    if($opt_v >= $level) {
        print STDERR $string;
    }
}

我希望那是有用的。

好的，不是在csh中，但这是我将$ HOME / bin添加到bash中的路径中的方法...

##代码##

品尝的季节...

十年来，我一直在使用以下(Bourne / Korn / POSIX / Bash)脚本：

##代码##

在Korn Shell中，我使用：

##代码##

这给我留下了PATH，它在最前面包含新的bin目录和其他bin目录，以及在主路径值中每个目录名称的一个副本，除了旧的bin目录和多余的bin目录都已删除bin。

我们必须对此进行调整以适应C Shell(对不起，但我坚信C Shell编程被认为有害)中阐明的真理。首先，我们不必摆弄冒号分隔符，因此生活实际上更轻松。

好吧，如果我们不在乎路径的顺序，则可以执行以下操作：

##代码##

这将对路径进行排序，并删除所有相同的其他路径。如果你有 。在路径中，我们可能需要使用grep -v删除它，并在最后将其重新添加。

这是一个长而未排序的单线：
设置路径=(echo $ path | tr''\ n'| perl -e'while(<>){打印$ _除非$ s {$ _} ++;}'| tr'\ n''')

dr_peper，

我通常更喜欢坚持使用我所居住的shell的脚本功能。使其更具可移植性。因此，我喜欢使用csh脚本的解决方案。我只是将其扩展为在localdirs中的每个目录上工作，以使其自己工作。

##代码##