Difference between revisions of "Sed"

Revision as of 12:51, 27 April 2010

Sed is a stream-editor in linux very useful to substitute string literals in files.

Examples

> sed -e "s/foo/bar/g" file1 file2

The above command will replace every occurence of foo with bar in file1 and file2

> find | sed -e "s/foo/bar/g"

The above command will replace every occurence of foo with bar in the stream returned by the find command.

> sed /^$/d

The above command will delete all empty lines

> sed -e 's/^[ \t]*//'

The above command will remove all leading/trailing blank spaces/tabs

> sed -e ':a;$!N;s/\n/ /;ta' file1 file2

The above command will join pairs of lines.

> sed -n '/^$/!{s/<[^>]*>//g;p;}'

The above command will remove all xml-like tags

>sed -e "s/\\\\/bar/g" file

The above command will replace every occurence of a backslash literal('\') with bar in file.

>for i in `find | grep -w dat`; do sed -e "s@\\\\@\/@g" $i > $i.bak; mv $i.bak $i;done

The above command in bash will substitute every occurence of '\' with '/' in every file returned by find that matches the '.dat' extension.

>for i in `find | grep -w dat`
 >do sed -e "s@D:\/Aplica\/MyModel@..\/..@g" $i > $i.bak
 >mv $i.bak $i
 >done

The above command will turn the paths into relative paths in every file .dat.

> for i in `find | grep Nomfich`
 >do j=`echo $i | tr [Nom] [nom]`
 >if [ $i != $j ]
 >then mv $i $j
 >fi
 >done;

The above command identifies all files names where the substring Nomfich occurs and renames them nomfich. This is useful as linux is case-sensitive and the program code must be case-coherent with the filenames.

Purge MohidWater .dat files

Execute these three lines from a putty session from within the directory of your current model:

>for i in `find | grep -w dat`; do sed -e "s@\\\\@\/@g" $i > $i.bak; mv $i.bak $i;done
>for i in `find | grep -w dat`; do sed -e "s@D:\/Aplica\/MyModel@..\/..@g" $i > $i.bak; mv $i.bak $i;done
> for i in `find | grep Nomfich`
 >do j=`echo $i | tr [Nom] [nom]`
 >if [ $i != $j ]
 >then mv $i $j
 >fi
 >done;

NOTE: replace D:\/Aplica\/MyModel with the path written in your model coming from Mohid GUI. Also note that replacing all "\" for "\/" is required. (This is explained in the regular expressions context).

MohidPurge

This is current version of the mohidpurge script:

#!/bin/bash
STRING=$1
#Changes in all .dat files '\' for '/'.
for i in `find | grep -w dat`; do
        sed -e "s@\\\\@\/@g" $i > $i.bak
        mv $i.bak $i
done
#Changes in all .dat files $path into '../..'.
for i in `find | grep -w dat`; do
        sed -e "s@$STRING@..\/..@g" $i > $i.bak
        mv $i.bak $i
done
#Renames all Nomfich files to nomfich.
for i in `find | grep Nomfich`; do
        j=`echo $i | tr [Nom] [nom]`
        if [ $i != $j ]; then
                mv $i $j
        fi
done