Update README.md

README.md

@@ -419,21 +419,14 @@ fileB    5    2    e
 e.g.  
 fileA:  
 1    0  
-
 2    1  
-
 3    1  
-
 4    0  
 
 fileB:  
-
 1    0  
-
 2    1  
-
 3    0  
-
 4    1  
     
 ```bash
@@ -441,11 +434,8 @@ awk -v OFS='\t' 'NR=FNR{a[$1]=$2;next} NF {print $1,((a[$1]=$2)? $2:"0")}' fileA
 ```
 
 1    0  
-
 2    1  
-
 3    0  
-
 4    0  
 
 ##### round all numbers of file (e.g. 2 significant figure)
@@ -470,11 +460,8 @@ e.g.
 seperate  
 
 David    cat,dog  
-
 into  
-
 David    cat  
-
 David    dog  
 
 detail here:　http://stackoverflow.com/questions/33408762/bash-turning-single-comma-separated-column-into-multi-line-string
@@ -745,21 +732,13 @@ for i in $(ls); do echo file $i;done
 wget -r -l1 -H -t1 -nd -N -np -A mp3 -e robots=off http://example.com
 ```
 //-r: recursive and download all links on page  
-
 //-l1: only one level link  
-
 //-H: span host, visit other hosts  
-
 //-t1: numbers of retries  
-
 //-nd: don't make new directories, download to here  
-
 //-N: turn on timestamp  
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 //-nd: no parent  
-
 //-A: type (seperate by ,)  
-
 //-e robots=off: ignore the robots.txt file which stop wget from crashing the site, sorry example.com  
 
 
@@ -1295,13 +1274,9 @@ head -c 50 file
 ##### group/combine rows into one row 
 
 e.g.  
-
 AAAA  
-
 BBBB  
-
 CCCC  
-
 DDDD  
 ```bash
 cat filename|paste - -