Shell Programming and Scripting

Hello,

this is my very first comment on this forum and i hope i don't mess it up. If i do, please forgive me (also for any language mistakes you may wanna know that i'm not native speaking).

As i just started doing a bigger paper for my studies i got a bunch of data in seperate csv-files which i'll have to analyze. Unfortunately the data logger messed up the naming for most of the files, so i have to fix that first in order to have a consistent naming. So i figured i'll write a little bash program for that. Here's roughly what i got so far:

Code:

#!/bin/bash
filelist="SP*"
echo "filenames" > filenames.dat
for file in $filelist
  do
	temp=$(head -1 $file)
#	echo "$temp" >> filenames.dat
	cp $file $temp
done

So what i'm doing is finding all files that have the string "SP" in it and add them to the list "filelist". Then i consecutively go through that list, open the file and save the first line in the variable "temp" (the correct name of the files is saved in that first line). Then i copy the files using the variable "temp" as new name.

Theoretically the first line consists of two tokens seperated by a semicolon (so two columns since csv-file), whereas i only need the first. But that's just an extra i don't necessarily need to work. The first line would be okay, too.

So my .csv-files look kinda like this:

Code:

SPY.SPYNODE.SIDE_R.IOM1.LaneA.SYSAP_IOM.SYSAP_IOM_IMU_READER.W_APPLI_IOM_IMU_READER_MEAS03_SigInsReceiveImuOutputToInsMeas03VelincY#VALUE;Integer
Timestamp;Value
1366346707344760064;0
1366346707360758016;0
1366346707376759040;0
1366346707392758016;0

As i thought it should work but did not ("Argument too long") i took a closer look to what actually happens. Apparently the head command doesn't work properly, so what i really does is saving the whole file (so including all the numbers also) in the variable "temp". If i then use that variable to create/copy my file the command is too long for the shell (actually the file consists of about 500 000 lines :-) ). So apparently the "head -1" doesn't work, but i don't know why. "head -n 1" didn't work either.

I have no idea what's going on and i don't know what i could change.

Can anybody help me out here and give me a piece of advice (i'd appreciate it if the advice was actually concerning this topic of course :-) ).

Thank you very much in advance.

Fa

Welcome FabianDe

That's a monster file-name you are thinking of creating. Are you sure you want to call it:-

Code:

SPY.SPYNODE.SIDE_R.IOM1.LaneA.SYSAP_IOM.SYSAP_IOM_IMU_READER.W_APPLI_IOM_IMU_READER_MEAS03_SigInsReceiveImuOutputToInsMeas03VelincY#VALUE;Integer
Timestamp;Value

..... as you are coding it?


What do you want to use for your file name? Is it just part of the first record?


Can you show us what a simple head -1 filename gives you for a sample file. if it ends up as lots of output, just trim it off after 3 rows.


I'm sure we can help.



Can we slim you code down a little too to concentrate of the actual issue you have:-

Code:

#!/bin/bash

for file in SP*
do
   temp=$(head -1 $file)
   cp $file $temp
done

Robin
Liverpool/Blackburn
UK