Check if a file exists with certain prefix

Shell Programming and Scripting
1

Hi guys,
How would i check a file exists with certainprefix? i have a directory with some files:
ABC1
ABC2
ABC3
etc..

and want to do:
please note i am using the korn shell environment.As when i gone through some stuff on then net i came to know some of the options will work differently based on the working shell environment.tht's wy i am specially mentioning my envrionment.

Code:
if [file exists with prefix ABC*] then
do something
else
do something else
fi

Any one could help me on this!!!!!

Advanced Thanks
Narasimharao.

2

use find command.. go through man page..try to do it your self

3

vidyadhar's solution is also a good way to go but if you want something in ksh:

#!/bin/ksh

if [ -f ABC* ]
then
	echo file exists.
else
	echo not
fi
4

Hi redoubtable,
the below code is working for only exact file names(i mean the -f option).could you please tell me the way for finding files with certain prefix.I know the find command.but i need another way by using simple if command and along with their options.

Hi can any one please help me on this..........

Advanced Thanks
Narasimharao.

5

The code I gave you works for filenames starting with "ABC".
ABC1, ABC2, ABC3.

redoubtable@Tsunami ~ $ ls -l ABC*
-rw-r--r-- 1 root root 0 2008-08-19 11:42 ABC1
-rw-r--r-- 1 root root 0 2008-08-19 11:42 ABC2
-rw-r--r-- 1 root root 0 2008-08-19 11:42 ABC3
redoubtable@Tsunami ~ $ 

redoubtable@Tsunami ~ $ ./s.ksh 
file exists.
redoubtable@Tsunami ~ $ cat s.ksh 
#!/bin/ksh

if [ -f ABC* ]
then
	echo file exists.
else
	echo not
fi
redoubtable@Tsunami ~ $

The '*' provides the capability of matching not only exact file names but also every file name starting with ABC. Remember that you must not use " in ABC.

Example:
This is ok:

if [ -f ABC* ]

This is wrong:

if [ -f "ABC*" ]
6

You can do something like this:

for file in *; do
  prefix=echo ${file:0:3}
  if [ "$prefix" = "ABC" ];  then
    # do something
  else
    # do something else
  fi
done

Regards

7

Hi Franklin52,
what i remember is the bash counts the number of the variable from 0, isn't it ?
so, I think that should be:

prefix=echo ${file:0:3}

Regards

8

You're right, thanks!

Regards

9

hi redoubtable,

                  Thanks for your information.now the code is working fine but  with if [ -a abc* ] not with  [-f abc* ] .i dont know wy -f option is not working.

Thanks
Narasimharao.

10

Hi Franklin52,
"prefix=echo ${file:0:3}" when i am placing this code in my korn shell environment it is throwing a warning by saying "The specified substitution is not valid for this command". i think it is specific to evironment.
Can you please tell me the how would i write the same syntax in a korn shell enviroment?

Advanced thanks!!!!
Narasimharao.

11

-f works only for ordinary files. -a works for any file. I'm glad you found a solution.

12 
prefix=`echo $file|sed 's/\(...\).*/\1/'`

or:

prefix=`echo $file|awk '{print substr($0,1,3)}'`

Regards