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HP-UX *** B.11.31 U ia64 ***unlimited-user license

I want to move a file in the current directory called abc.txt to a directory called ./begperl. While I do so I want the moved version of the file to be named as ab.txt.What I want is to remove a predefined string from the filename and move it, and delete the original file based on one more third variable=Y/N. I have tried the below oneliners in vain.

awk -v name=abc.txt -v dir=begperl 'BEGIN{ renamed_var=substr("c", "", name);system("mv " name  "./"dir/renamed_var)}' 

awk -v name=abc.txt -v dir=begperl 'BEGIN{ renamed_var=substr("c", "", name); print renamed_var}'

awk -v name=abc.txt -v dir=begperl 'BEGIN{ print substr("c", "", name) }'


awk -v name=abc.txt -v dir=begperl -v variable_two=substr("c", "", name){print variable_two}' 


awk -v name=abc.txt -v dir=begperl -v variable_two=substr("c", "", name){print variable_two}'

The only one liner that I got working is 

awk -v name=abc.txt -v dir=begperl 'BEGIN{ system("mv " name " ./"dir)}'

Immense thanks

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1  
You have a couple of issues with your code. awk's substr() function expects a string as first argument and an index and a length as second and (optional) third argument. I also see a general design problem; you are doing primitive string operations and then invoke a shell (by using system(). Instead this sort of task could better be done completely in a shell. –  Janis Apr 1 at 11:39

3 Answers 3

up vote 3 down vote

Why are you using awk for this? If you have both the original and the target name, why not just mv abc.txt begperl/ab.txt?

If you don't have the target name and just want to remove a character from the original, you can do it in the shell. Again, no need for awk:

file="abc.txt"; mv "$file" begperl/"${file//c}"

That will remove all occurrences of c from $file. To remove the first one only, use

file="abc.txt"; mv "$file" begperl/"${file/c}"

Alternatively, you could do

mv abc.txt begperl/"$(echo "abc.txt" | sed 's/c//')"
share|improve this answer
    
need one liner. Remove a string from filename, copy to some other directory, delete original based on the value of a variable. Looked like awk could do it. –  user3146086 Apr 1 at 11:57
    
Some shells do not allow such substitution like ${file/c}. In the case can help ${file%c*}${file#*c} –  Costas Apr 1 at 11:59
    
@Costas good point about that not being present in all shells. However, your alternatives remove everything after the last c or everything up to the first c. Neither is what the OP requested. –  terdon♦ Apr 1 at 12:07
    
@user3146086 Well, those are one-liners really. Anyway, see updated for another way. Launching awk with an internal system call is just overkill. –  terdon♦ Apr 1 at 12:08
up vote 3 down vote

You need the sub (substitute) rather than the substr (substring) command: compare

$ awk -v name="abc.txt" 'BEGIN {substr("c","",name) ; print name}'
abc.txt

with

$ awk -v name="abc.txt" 'BEGIN {sub("c","",name) ; print name}'
ab.txt

However unless you are doing this as a programming exercise to learn awk, there really is no reason not to use your shell for things like this e.g. in bash:

newname="${name%c.*}.${name##*.}"

forms a string from name with the shortest trailing match starting with c. removed, concatenated with the dot extension formed by removing the longest portion matching up to .

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can we do it without echo? –  user3146086 Apr 1 at 11:46
    
@user3146086 afaik awk needs to read something - either from a file, or from standard input: the piped echo is just a way to provide that. But TBH unless you are just doing this as a programming exercise, there is no reason at all to use awk here. –  steeldriver Apr 1 at 11:51
    
If you use BEGIN term there is no need to read from anywhere: awk -v name="abc.txt" 'BEGIN{sub("c","",name) ; print name}' –  Costas Apr 1 at 13:10
    
@Costas doh! thanks, answer amended accordingly –  steeldriver Apr 1 at 13:51
up vote 0 down vote

I am the OP. I dont think this is as easy as I thought it would be to be implemented in a one liner. I think I wil work on this one liner later(Or never ;-))

#!/usr/bin/ksh
ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE=$1
REMOVE_STRING_VARIABLE=$2
DELETE_ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE=$3
if [[ $# -ne 3 ]]
then
echo "Script requires three parameters. First:Filename with path. Second:String to remove from filename. Third:Y or N to delete file"
exit 1
fi
ORIGINAL_FILE_NAME_VARIABLE=`echo  ${ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE} | awk -F '/' '{print $NF}'`
#echo ${ORIGINAL_FILE_NAME_VARIABLE}
AMENDED_FILE_NAME_VARIABLE=`echo ${ORIGINAL_FILE_NAME_VARIABLE} | sed "s/${REMOVE_STRING_VARIABLE}//g"`
#echo ${AMENDED_FILE_NAME_VARIABLE}
ORIGINAL_FILE_LOCATION_DIR=`echo ${ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE} | awk 'BEGIN{FS=OFS="/"}{$NF=""; NF--; print}'`
if [[ -f ${ORIGINAL_FILE_LOCATION_DIR}/${AMENDED_FILE_NAME_VARIABLE} ]]
then
AMENDED_FILE_NAME_VARIABLE=${AMENDED_FILE_NAME_VARIABLE}_$$_$$
fi
echo ${ORIGINAL_FILE_NAME_VARIABLE}|grep -q ${REMOVE_STRING_VARIABLE}
if [[ $? -ne 1 ]] 
then
cp ${ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE} ${ORIGINAL_FILE_LOCATION_DIR}/${AMENDED_FILE_NAME_VARIABLE}
if [[ ${DELETE_ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE} = 'y' || ${DELETE_ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE} = 'Y' ]]
then
rm ${ORIGINAL_FILE_NAME_WITH_PATH_VARIABLE}
fi
fi

But I really thought this was possible in a one liner. I am the OP.Comments?

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