Shell Programming and Scripting

Hi,

I have multiple files where it starts with test1.c, test2.c,test3.c and so on.

I would like to get each file separately to perform abstraction from these files.

I tried something like:-

for t in ./*
filenumber=${t:4} # to cut the "test" in order to get the number

cat test$filenumber.c| sed 's/^[ ]*//' >final.txt

However, in my folder, there is other potential file other than test1.c,test2.c...in other words, there are other files in the folder.

Is there other better way to grab the number so that each file can be catenate automatically?


Please advise. Thanks.


-Jason

Not sure what you're trying to accomplish here. Your loop overwrites "final.txt" so that only the last testN.c is within it. If you're looking to combine:

Code:

for t in ./test*.c; do
  sed 's/^[ \t]*//' $t >> final.txt
done

Hi,

Thanks for the prompt reply.

I used the concept you mentioned and basically it is printing out the file contents.

What that I am currently looking for is getting a number from the file name itself in a folder.
Means I have folder A where i have multiples file name; test1.c, test2.c, test3.c...and so on.

I would like to grep the number of 1,2,3,....so that I can open each of test$grepnumber.c to do sed operation and finally append to an output file.

$grepnumber refers to the number of each file name exist in folder A.

Hope this is much clearer than before.Thanks.

First off, it seems to me that you do not even need to extract the number from the filename if you are going to use the complete filename anyways. It would be sufficient to filter out all the files matching a certain name pattern, like "test, followed by a number and having a .c-extension".

There is a group of metacharacters (aka "wildcards"), that are interpreted by the shell: everybody knows "?" and "*", but there are others, which will exactly do what you intend to do: "[]" searches for a single character of the list of characters enclosed in the brackets, for instance: "[0-9]" will find every single digit number.

To search and find only the files you want to find use an expression like "test[0-9].c". If you need the (more powerful) regexps of sed to prepare the list capture the output of "ls" in a pipeline and use sed to work on it. Use a while-loop to further do some work on the files found this way, the following is an example:

Code:

The shell way:
ls -1 /path/to/dir/test[0-9].c| while read fIn ; do
     iNumber="$(print - "$fIn" | sed 's/^test//;s/.c//')"
     print - "Files name is: $fIn"
     print - ".... and its number is $iNumber"
done

...and the regexp way:
ls -1 /path/to/dir | sed -n '/^test[0-9][0-9]*\.c/ p' | while read fIn ; do
     iNumber="$(print - "$fIn" | sed 's/^test//;s/.c//')"
     print - "Files name is: $fIn"
     print - ".... and its number is $iNumber"
done

I hope this helps.

bakunin