How to batch files in shell script? - bash

Question

I would like to build a shell script to automatically archive object files into a static library, and copy all the headers and .a file to desired directory.
However, as the number of obj files grows, the following mess gets worse:
8 CWD=$(pwd)
9
10 FILE1="SDL_Logger.o"
11 HEADER1="SDL_Logger.h"
12 FILE2="SDL_Initializer.o"
13 HEADER2="SDL_Logger.h"
14 ARC="libsdlhelper.a"
15
16 INCLUDE=~/include
17 LIB=~/lib
18
19 if [ ! -f $FILE1 ];
20 then
21 echo " error: file $FILE1 does not exist. Abort."
22 else
23 if [ ! -f $FILE2 ];
24 then
25 echo " error: file $FILE2 does not exist. Abort."
26 else
27 echo " building archive... "
28 ar rs $ARC $FILE1 $FILE2
29
31 # lib
32 cp $ARC $LIB
34
35 # include
36 cp $HEADER1 $INCLUDE
37 cp $HEADER2 $INCLUDE
39
41 fi
42 fi
So, if I were to group all files into ONE variable like:
FILE="obj1.o obj2.o ... "
How would I check the existence of each file, and copy them(headers)? I can only do this one by one, which will be soon unacceptable.

Answer 1

Here is what I came up with to help you.
The best way to do this is using an array for FILE
short example to implement what you are trying to do:
# !/bin/bash
#define an array of files to look for
FILES=("SDL_Logger.h" "SDL_Initializer.h" "libsdlhelpere.o")
#define your directories
INCLUDE=~/include
LIB=~/lib
#set the amount of entries in our array
SIZE=${#FILES[#]}
# use for loop read all FILES
for (( i=0; i<${SIZE}; i++ ));
do
echo "checking for file: "${FILES[$i]}
if [ ! -f ${FILES[$i]} ];
then
echo " error: file"${FILES[$i]}" does not exist. Abort."
else
echo " building archive... "
fi
done
Here we define FILES as our array
FILES=("SDL_Logger.h" "SDL_Initializer.h" "libsdlhelpere.a")
then we Find the size of files
SIZE=${#FILES[#]}
Then we go through each file and execute a command which is echo and then our if statement:
for (( i=0; i<${SIZE}; i++ ));
do
Here is how we call our item in the array...
${FILES[$i]}
so in what we are doing in plain english is:
echo FILES[1]....
IF FILES[1] doesn't exist then error....
else execute building archive...
echo FILES[2]....
IF FILES[2] doesn't exist then error...
etc...
This will repeat until the SIZE of FILES in met.
Using this method you can also just define the beginning part of the file name such as
"SDL_Initializer" and have your loop add in the .o .h. .a etc... Maybe another array FILETYPES ;)
hope this helped...
Sorry I didn't complete the code for you :)

Answer 2

Here is an answer to the question as asked:
#!/bin/bash
FILES="SDL_Logger.o SDL_Initializer.o"
HEADERS="${FILES//.o/.h}"
ARC="libsdlhelper.a"
INCLUDE=~/include
LIB=~/lib
for f in ${FILES}; do
if [ ! -f "${f}" ]; then
echo "error: file ${f} does not exist. Abort."
exit 1
fi
done
ar rs ${ARC} ${FILES}
cp ${ARC} ${LIB}
cp ${HEADERS} ${INCLUDE}
However, as the comments point out, the right tool for this job is make. For example GNU make. If you plan on developing software on a unix platform, investing time learning make is time well spent.