#! /bin/bash## original from:# vtree: visual directory tree# @(#) vtree.sh 1.1 91/07/01# 90/04 john h. dubois iii (john@armory.com)# 91/07/01 fixed bug that caused problems when dir given on command line,#          added some info to help, changed to 4-space indenting## conversion to bash v2 syntax done by Chet Ramey#help=\"Syntax: vtree [startdir] [namelen=#] [linelen=#]If startdir is not specified, tree will start at current dir.namelen specifies the minimum number of characters of a directory name thatare guaranteed to be printed.This is a tradeoff between the number of tree levels that can fit on ascreen line and the number of chars of each dir name that can be printed.In most cases it will be possible to print more than namelen characters ofthe name (a name up to namelen+1 chars will always be printed in full),but in some cases truncation down to namelen chars will occur.If truncation occurs, a '>' is printed at the end of the name.namelen=8 (the default) typically causes about 5 dirs/1000 to be truncated.namelen=7 typically causes about 10 dirs/1000 to be truncated.namelen=8 will allow 6 full length dirs to be printed in 79 columns.namelen=7 will allow 7 full length dirs to be printed in 79 columns;linelen specifies the maximum number of characters to print on one screenline.  All characters beyond this are truncated.  The default is 1024.To avoid line wrap on an 80 column terminal with autowrap, use linelen=79."for i in "$@"; do    case $i in    -h) echo "$help"; exit;;    *=*)        vars="$vars $i"        ;;    *)        if [ ! -x $i ] || [ ! -d $i ]; then     # arg must be a dir and executable            echo "$i: directory not accessible."            exit        fi        cd $i        ;;    esac    shiftdonepwd     # print path of root of tree# find all directories depth first; ignore permission errorsfind . -type d -print 2> /dev/null | \gawk -F/ '# Do this block for NR == 1 instead of BEGIN because command line var# assignments are not done until after BEGIN block is executed.NR == 1 {    if (namelen)        MaxLen = namelen;    else        MaxLen = 8;    if (!linelen)        linelen = 1024    HSpace = substr("              ",1,MaxLen);     # used to indent tree    n = 0;          # number of dirs found on one major branch}$0 != "." {     # do for every line produced by find except tree root dir    if (NF == 2 && n > 0)   # print major branch whenever a new one starts        list();    Depth[n] = NF - 1;      # record depth and name of dir     Name[n++] = $NF;}END {    list()  # print last major branch}function list() {    Line = Name[0];     # initialize first line of branch to be branch base    for (i = 1; i < n; i++) {   # for each name in major branch        if (Depth[i] == Depth[i-1] + 1)            AddHLink(); # if moving deeper into branch, use same line        else {            print substr(Line,1,linelen);   # last line is done; print it            Line = "";  # start new line            # print indentation, vert links, and vert/horiz links            for (d = 1; d < Depth[i] - 1; d++)  # for each level of indentation                # if a vert. link has been established for this level                if (VLink[d])                    Line = Line HSpace " |  ";                else        # print empty indentation                    Line = Line HSpace "    ";            # Print last part of vert. link            if (VLink[d] == i) {                VLink[d] = 0;   # mark level for no vert link                Line = Line HSpace " \\--";            }            else                Line = Line HSpace " |--";        }        Line = Line Name[i];    # Add dir name to line    }    print substr(Line,1,linelen);   # print last line of major branch    n = 0;      # reset name counter}function AddHLink() {    NDepth = Depth[i];  # Depth of this name    VLink[NDepth - 1] = 0;    # search until a name found at a level less than this one    for (j = i + 1; j < n && Depth[j] >= NDepth; j++)        # keep track of last name that VLink should connect to        if (Depth[j] == NDepth)            VLink[NDepth - 1] = j;    if (VLink[NDepth - 1]) {        NLine = substr(Line,1,(NDepth - 2) * (MaxLen + 4) + MaxLen + 1);        if (length(NLine) < length(Line))            Line = substr(NLine,1,length(NLine) - 1) ">"        else            Line = NLine;        Line = Line substr("--------------+--",            18 - ((NDepth - 1) * (MaxLen + 4) - length(Line)));    }    else {        NLine = substr(Line,1,(NDepth - 2) * (MaxLen + 4) + MaxLen + 3);        if (length(NLine) < length(Line))            Line = substr(NLine,1,length(NLine) - 1) ">"        else            Line = NLine;        Line = Line substr("-----------------",            1,(NDepth - 1) * (MaxLen + 4) - length(Line));    }}' $vars