Linux Tips and Tricks

Linux Tips and Tricks

Do’s and Dont’s in shell scripting

December22

Do’s and Dont’s in shell scripting

1) Dont use Grep and Cat command together

Wrong way :

1
$cat filename | grep "pattern"

Correct way :

1
$grep "pattern" filename

2) Dont use cat,grep and wc commands together

Wrong way :

To count the number of occurence

1
$cat filename | grep "pattern" | wc -l

Correct way :

1
$grep -c "pattern" filename

3) dont use sort and uniq together ( to eliminate the duplicate entires )

Wrong way :

1
$sort filename | uniq

Correct way :

1
$sort -u filename

4) Dont use grep and awk together

wrong way :

1
$ grep "pattern" filename | awk '{print $1}'

correct way :

1
$ awk '/pattern/ {print $1}' filename

5) Dont use ls in for loop ( to manipulate the files )

wrong way :

1
2
for i in `ls` ; do echo $i; done
for i in `ls *.txt`; do echo $i; done

Correct way :

1
2
for i in *; do echo $i; done
for i in *.txt; do echo $i; done
posted under Uncategorized

Email will not be published

Website example

Your Comment:


Recent Comments

    Categories