Replacing characters in multiple file names
by Zubair on May.05, 2010, under Technology, Unix programming
I had a large set of shell scripts each of which i needed to run on separate planetLab nodes for which I included the name of the vantage point in every file. I had a pre-string to every file name which i then needed to replace. Unix/Linux makes this things so much more easier in this case.
Original name of file(s): tcpTrace-[vantageName-1].sh
I needed to change the inital string name from tcpTrace to pingTrace: Final name of file(s): pingTrace-[vantageName-1].sh
Since there was over 250 such files in my directory – a manual rename would be really tedious. I wrote the following rather simple shell script to do the job:
#!/bin/bashfor file in tcpTrace*.shdomv $file pingTrace${file#tcpTrace}done
I use a simple but rather obscure string operator here, the ‘#’. Generally, we know that anything following the # in a shell script is ignored as a comment (except the first line of course). However, the ‘#’ sign can be used within a shell variable to carry out a delete operation. ‘#’ here means that to ‘delete from the left to the first case of what follows’. Further info is here.
In my case, i first add the string ‘pingTrace’ to the start of the file, then take the filename (stored in $file) and delete from that variable, starting from the left till the first case of when ‘tcpTrace’ is encountered. Simple and really effective fix.
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