KSH 是否有等效于 bash pushd/popd 的内置命令?
对于那些不知道 bash 中的 pushd 和 popd 做什么的人,这里是手册页中的描述
pushd [-n] [dir]
pushd [-n] [+n] [-n]
Adds a directory to the top of the directory stack, or rotates
the stack, making the new top of the stack the current working
directory. With no arguments, exchanges the top two directo-
ries and returns 0, unless the directory stack is empty.
popd [-n] [+n] [-n]
Removes entries from the directory stack. With no arguments,
removes the top directory from the stack, and performs a cd to
the new top directory. Arguments, if supplied, have the fol-
lowing meanings:
谢谢
最佳答案
当我发现 ksh 不包括这些时,我自己写了一个。我把它放在 ~/bin/dirstack.ksh
中,我的 .kshrc
文件像这样包含它:
. ~/bin/dirstack.ksh
dirstack.ksh
的内容如下:
# Implement a csh-like directory stack in ksh
#
# environment variable dir_stack contains all directory entries except
# the current directory
unset dir_stack
export dir_stack
# Three forms of the pushd command:
# pushd - swap the top two stack entries
# pushd +3 - swap top stack entry and entry 3 from top
# pushd newdir - cd to newdir, creating new stack entry
function pushd
{
sd=${#dir_stack[*]} # get total stack depth
if [ $1 ] ; then
if [ ${1#\+[0-9]*} ] ; then
# ======= "pushd dir" =======
# is "dir" reachable?
if [ `(cd $1) 2>/dev/null; echo $?` -ne 0 ] ; then
cd $1 # get the actual shell error message
return 1 # return complaint status
fi
# yes, we can reach the new directory; continue
(( sd = sd + 1 )) # stack gets one deeper
dir_stack[sd]=$PWD
cd $1
# check for duplicate stack entries
# current "top of stack" = ids; compare ids+dsdel to $PWD
# either "ids" or "dsdel" must increment with each loop
#
(( ids = 1 )) # loop from bottom of stack up
(( dsdel = 0 )) # no deleted entries yet
while [ ids+dsdel -le sd ] ; do
if [ "${dir_stack[ids+dsdel]}" = "$PWD" ] ; then
(( dsdel = dsdel + 1 )) # logically remove duplicate
else
if [ dsdel -gt 0 ] ; then # copy down
dir_stack[ids]="${dir_stack[ids+dsdel]}"
fi
(( ids = ids + 1 ))
fi
done
# delete any junk left at stack top (after deleting dups)
while [ ids -le sd ] ; do
unset dir_stack[ids]
(( ids = ids + 1 ))
done
unset ids
unset dsdel
else
# ======= "pushd +n" =======
(( sd = sd + 1 - ${1#\+} )) # Go 'n - 1' down from the stack top
if [ sd -lt 1 ] ; then (( sd = 1 )) ; fi
cd ${dir_stack[sd]} # Swap stack top with +n position
dir_stack[sd]=$OLDPWD
fi
else
# ======= "pushd" =======
cd ${dir_stack[sd]} # Swap stack top with +1 position
dir_stack[sd]=$OLDPWD
fi
}
function popd
{
sd=${#dir_stack[*]}
if [ $sd -gt 0 ] ; then
cd ${dir_stack[sd]}
unset dir_stack[sd]
else
cd ~
fi
}
function dirs
{
echo "0: $PWD"
sd=${#dir_stack[*]}
(( ind = 1 ))
while [ $sd -gt 0 ]
do
echo "$ind: ${dir_stack[sd]}"
(( sd = sd - 1 ))
(( ind = ind + 1 ))
done
}
关于bash - ksh 上的 pushd/popd?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/984635/