E Constant

一个获得相对路径的脚本
小例子：

$ getrelpath d:/HelloWorld/b d:/HelloWorld/a/bbb/c.jpg
../a/bbb/c.jpg

源文件：

#!/bin/bash
# get relative pathname of a file from a given dir
# Michael.Fantasia@Gmail.com

if [ "$#" -ne "2" ]
then
    echo "Usage: $(basename $0) dirname filename" >&2
    exit 1
fi

dirname=$(echo $1/ | sed 's@/*$@/@')
if [ -d "$2" ]
then
    filename=$(echo $2/ | sed 's@/*$@/@')
else
    filename=$2
fi
path='[^/]*/'
i=1

while [ "$i" -ne "0" ]
do
    pathdir=$(k=0;while [ "$k" -lt "$i" ];do echo -n $path;((k=k+1));done)
    str1=$(expr "$dirname" : '('"$pathdir"')')
    str2=$(expr "$filename" : '('"$pathdir"')')
    if [ "$str1" != "$str2" -o -z "$str1" ]
    then
        ((i=i-1))
        break
    fi
    ((i=i+1))
done

if [ "$i" -eq "0" ]
then
    echo $2
    exit 0
fi

pathdir=$(k=0;while [ "$k" -lt "$i" ];do echo -n $path;((k=k+1));done)
str1=$(echo $(expr "$dirname" : "$pathdir"'(.*)')/ | sed 's@/*$@/@;s@[^/]+@..@g')
str2=$(expr "$filename" : "$pathdir"'(.*)')
echo $str1$str2 | sed 's@^/@./@'

exit 0

从国家地理网站下载每日图片

#!/bin/bash
# picngs: Download today's picture from National Geographics website
# Michael.Fantasia@Gmail.com
# arg1: datefmt
# arg2: picdir

# export LC_ALL=C

BADDATE=66
WEBFAILURE=67
SEDFAILURE=68

pntmp=$(basename "$0")_$$

picdir=${2:-"${HOME}/Pictures/Photography"}

cd /tmp

if [ $# -eq 0 ]
then
    mfdate=$(date +%Y.%m.%d)
    wget -q "http://photography.nationalgeographic.com/photography/photo-of-the-day/" -O $pntmp
else
    if date -d "$1" +%Y-%m-%d 2>/dev/null
    then
        mfdate=$(date -d $1 +%Y.%m.%d)
        mfdate2=$(date -d $1 +"%B %e, %Y" | sed 's/ +/ /g')
        wget -q "http://photography.nationalgeographic.com/photography/photo-of-the-day/archive/?page=1&month=$(date -d $1 +%m)&year=$(date -d $1 +%Y)" -O "$pntmp"_search
        if [ $? -ne 0 ]
        then
            echo "Error in finding picture." >&2
            exit $WEBFAILURE
        fi
        papername=$(sed -n '/'"$mfdate2"'/,/</div>/p' "$pntmp"_search | sed 's/</n/g' | grep '^a href' | grep 'photo-of-the-day' | head -n1 | cut -d'"' -f2)
        wget -q "http://photography.nationalgeographic.com$papername" -O $pntmp
    else
        echo "Unknown date format." >&2
        exit $BADDATE
    fi
fi

picname=$mfdate-$(sed -n 's/.*<h1>([^<]*)</h1>.*/1/p' $pntmp | sed 's/['"'"',"]//g;s/ +$//;s/ +/_/g;s///_/g;'"s/&#039/'/g" | tr '[:upper:]' '[:lower:]')
findname=$(sed 's/</div>/n/g' $pntmp | grep 'Download Wallpaper' | sed 's/</n/g' | grep '^a href' | head -n1 | cut -d'"' -f2)
if [ "$findname" = "" ]
then
    #findname=$(sed -n '/primary_photo/,/</div>/p' $pntmp | sed 's/</n/g' | grep '^img src' | grep 'ngeo' | head -n1 | cut -d'"' -f2)
    findname=$(sed -n '/primary_photo/,/</div>/p' $pntmp | sed 's/</n/g' | grep '^img src' | cut -d'"' -f2)
fi

if [ -z "$findname" ]
then
    echo "No picture found." >&2
    exit $SEDFAILURE
fi

wget -q -c "$findname" -O $picname.jpg

if [ $? -ne 0 ]
then
    echo "Error in downloading picture." >&2
    exit $WEBFAILURE
else
    mfdate=$(echo $mfdate | sed 's/.//g')
    mkdir -p $picdir/$(date -d $mfdate +%Y)
    mv $picname.jpg $picdir/$(date -d $mfdate +%Y)/
    open $picdir/$(date -d $mfdate +%Y)/$picname.jpg
fi

echo "Done."
growlnotify --image "$picdir/$(date -d $mfdate +%Y)/$picname.jpg" -m "National Geographic Picture of the Day $mfdate downloaded."

exit 0