summaryrefslogtreecommitdiffstats
path: root/examples/functions/dirstack
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--examples/functions/dirstack160
1 files changed, 160 insertions, 0 deletions
diff --git a/examples/functions/dirstack b/examples/functions/dirstack
new file mode 100644
index 0000000..d68e619
--- /dev/null
+++ b/examples/functions/dirstack
@@ -0,0 +1,160 @@
+#!/bin/bash
+# @(#) dirstack
+
+###
+# Another implementation of the directory manipulation functions
+# published in the Bolsky & Korn book : "The new Korn shell" :
+# cd, to change current directory
+# d, to display the stack content
+# Eric Sanchis (eric.sanchis@iut-rodez.fr), 2012
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+###
+
+
+shopt -s expand_aliases
+shopt -s extglob
+shopt -s cdable_vars
+
+alias integer='declare -i'
+
+integer MAX=32
+integer INDMAX=MAX-1
+integer INDTOP=0
+
+unalias cd 2>/dev/null
+alias cd=cdir
+
+unset tab
+tab[INDTOP]="$(pwd)"
+
+
+function cdir
+{
+ local -i ind
+ local dir
+
+dir="${1:-$HOME}"
+case "$dir" in
+ - ) # cd - => equivalent to : cd -1
+ ind=INDTOP-1
+ cd_by_number $ind
+ ;;
+ -+([[:digit:]]) ) # cd -n
+ ind=$INDTOP-${dir#-}
+ cd_by_number $ind
+ ;;
+ *) # cd ~ or cd dir_name
+ cd_by_name "$dir"
+esac
+}
+
+
+function cd_by_number
+{
+ local -i k=$1
+ local -i j
+ local dirtmp
+
+if (( k < 0 ))
+ then
+ echo Impossible to change directory >&2
+ return 1
+ else
+ dirtmp="${tab[k]}"
+ j=k+1
+ while (( j <= INDTOP ))
+ do
+ tab[j-1]="${tab[j]}"
+ j=j+1
+ done
+ tab[INDTOP]="$dirtmp"
+ \cd "${tab[INDTOP]}"
+fi
+}
+
+
+function cd_by_name
+{
+ local -i i
+ local rep
+
+rep=$( \cd "$1" &>/dev/null && pwd)
+if [[ -z "$rep" ]]
+ then
+ echo cd : "$1" unknown >&2
+ return 1
+fi
+
+ i=$INDTOP
+ while (( i >= 0 ))
+ do
+ if [[ "${tab[i]}" == "$rep" ]]
+ then break
+ fi
+ i=i-1
+ done
+
+if (( i == INDTOP ))
+ then # cd -0 => we do nothing !
+ return 0
+ elif (( i == -1 ))
+ then # the directory isn't in the stack
+ if (( INDTOP == INDMAX ))
+ then # the stack is FULL
+ # the oldest directory is removed
+ local -i m
+
+ m=1
+ while (( m <= INDMAX ))
+ do
+ tab[m-1]="${tab[m]}"
+ m=m+1
+ done
+ else # the new directory is added to the top of the stack
+ INDTOP=INDTOP+1
+ fi
+ tab[INDTOP]="$rep"
+ \cd "${tab[INDTOP]}"
+ return 0
+
+ else # the directory is already in the stack
+ # $i gives its index
+ cd_by_number $i
+fi
+}
+
+
+function d # display the directory stack
+{
+ local -i i
+ local rep
+
+i=0
+while (( $i <= $INDTOP ))
+ do
+ rep="${tab[INDTOP-i]#$HOME/}"
+ case "$rep" in
+ $HOME) rep="~" ;;
+ /* ) : ;;
+ * ) rep="~/$rep"
+ esac
+
+ echo "$i ) $rep"
+ i=i+1
+ done
+}
+
+