My task is, to write a "one-line" command, which must use ls and awk.
Task: Write a command-line, which should rename all files in dir from form "value1.dok" to "value2.doc". And value2=value1+1.
For example:
Code:
ls | awk -F: '{print "mv "$0" "$1+1".doc"}' | sh
But this doesn't work with a filename with characters. Therefore i tested this:
Code:
ls | awk -F: '{print "mv "$0" value"substr($1 ,6)+1".doc"}' | sh
This worked, but my taskprogram say "wrong" and want see a other command (perhaps with different string?)
So i tested it with regular expressions, but my console say always "syntax error":
Code:
ls | awk -F: '{print "mv "$0" "${1%[!0-9]*}""${1%[0-9]*}+1".doc"}' | sh
I havent any idea how i could it bring to work in one line...
Can someone perhaps help me?
And sorry for my very bad english
Is this a homework assignment? If so, note that the homework can only be posted in a special forum following the rules noted here.
If it is not a homework assignment, why is a one-liner a requirement (most computer professionals prefer readable, maintainable code)?
Why are ls and awk requirements when this can all (except for the mv) be done with just shell built-ins?
What shell and OS (including version) are you using?
I don't understand why you were using -F: in your awk scripts when there aren't any colons in your filenames. Here are a couple of ways to do it; one using ls, awk, rm, and bash; and the other one just using bash and rm. Both are presented in readable format and in 1-liner format:
Code:
#!/bin/bash
echo 'ls | awk | bash:'
ls | awk '
/[0-9][.]dok$/ {
match($0, "[0-9]*[.]dok$")
printf("echo mv \"%s\" \"%s%s.doc\"\n", $0, substr($0, 1, RSTART-1),
substr($0, RSTART, length($0) - RSTART - 3) + 1)
}' | bash
printf '\n\nbash/ksh built-ins:\n'
for f in *[0-9].dok
do b=${f%.dok}
s=${b##*[!0-9]}
b=${b%%[[0-9]*}
echo mv "$f" "$b$((s+1)).doc"
done
printf '\n\nls | awk | bash 1-liner:\n'
ls|awk '/[0-9][.]dok$/{match($0,"[0-9]*[.]dok$");printf("echo mv \"%s\" \"%s%s.doc\"\n",$0,substr($0,1,RSTART-1),substr($0,RSTART,length($0)-RSTART-3)+1)}'|bash
printf '\n\nbash/ksh built-ins 1-liner:\n'
for f in *[0-9].dok;do b=${f%.dok};s=${b##*[!0-9]};b=${b%%[[0-9]*};echo mv "$f" "$b$((s+1)).doc";done
If you find one that prints the mv commands you want to execute, remove the echo shown in red to actually rename the files.
The parameter expansion extracting the sequence number from the pathname works as long as there is only one string of digits in the filenames being processed (just before the .dok). The ERE in the awk script doesn't have this limitation, but your description didn't indicate that there could be multiple strings of digits; so I assume both methods do what you need.
Neither of these will do what you want if there are leading zeros on the digit strings in your filenames (such as value0012.dok).
I would like to extract "JDBC Thin Client" from (PROGRAM=JDBC Thin Client); and "C:\Python26\python.exe" from (PROGRAM=C:\Python26\python.exe); "txm_v_awsrf_db.pr" from (PROGRAM=txm_v_awsrf_db.pr).
if input line like "(PROGRAM=)", it return unknown.
Would you help suggest a regular... (4 Replies)
Hi,
I am quite knew to scripting and I am trying to get a regular expression to work to check that a user enters a valid version number such as 1 or 1.1 or 12.3 etc. I dont seem to be able to get it to work as it picks up versions such as 1.......2. I only want it to work with a single dot.... (12 Replies)
Hello All,
I'm trying to extract the lines between two consecutive elements of an array from a file.
My array looks like:
problem_arr=(PRS111 PRS213 PRS234)
j=0
while } ]
do
k=`expr $j + 1`
sed -n "/${problem_arr}/,/${problem_arr}/p" problemid.txt
---some operation goes... (11 Replies)
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat";
open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat";
while (<DESTINATION_FILE>)
{
# print... (1 Reply)
CA_RELEASE has a value of 6. I need to check if that this is a numeric value. if not error.
source $CA_VERSION_DATA
if * ]
then
echo "CA_RELESE $CA_RELEASE is invalid"
exit -1
fi
+ source /etc/ncgl/ca_version_data
++ CA_PRODUCT_ID=samxts
++ CA_RELEASE=6
++ CA_WEEK_NO=7
++... (3 Replies)
I currently list and sort all the files in a directory which begin with an Upper Case C and end with the extension '#finished#'.
Here is the command I use:
ls -tr $currentDir/*.#finished#
what i need to do now is list all the files in a directory that begin with upper case C and end... (3 Replies)
What does the regular expression +~).*'] mean while using it with regexec.When the string "RCHNUSNT35C~rs07/ASM-RS07" is used with the regular expression +~).*'] regexec gives an error. I know what regexec does,but i do not understand what this expression means wrt to this string...
any help... (2 Replies)
Is it possible to combine a regular expression with a aritmetical expression? For example, taking a 8-numbers caracter sequece and casting each output of a grep, comparing to a constant.
THX! (2 Replies)
12-07-2014
