how to work at the same time with multiple files inside file name array in linux shell script?

Question

I have a shell script and i read all .s files in the specified folder first and then compile them to object file with a loop and after that link them to executable file. this:

FILES=PTscalar_1.0/mibenchforpt/security/sha/*.s

for sfile in $FILES 
do

echo "------------------------------------------------"
    echo $sfile
    objectFile="${sfile%.s}.o"
    exefile="${objectFile%.o}.ex"

    simplescalar/bin/sslittle-na-sstrix-as -o  $objectFile $sfile

done

but I have a problem: in sha mibench program we have 2 files that each of them is in this flow:

.c -> .s -> .o

but at the last stage two .o files should be linked into one executable file.

how I can get two file names at the same time and create a command to link them.

main code is this:

simplescalar/bin/sslittle-na-sstrix-ld -o __sha.ex _sha.o _sha_driver.o

is there any way to see inside of FILES like this:

OFILES=PTscalar_1.0/mibenchforpt/security/sha/*.o
simplescalar/bin/sslittle-na-sstrix-ld -o $exefile OFILES[0] OFILES[1]

and after that doing that in a loop for all files with this pattern first file is like *.o or *_main.o second is: *_driver.o

Thanks

Answer 1

I created this file and it worked:

#!/bin/bash
#compile to assembly:

FILES=*_driver.s

for sdriverfile in $FILES 
do

echo "------------------------------------------------"
# s file
    echo $sdriverfile
    sfile="${sdriverfile%_driver.s}.s"
    echo $sfile

# object files
    obj="${sfile%.s}.o"
    obj_driver="${sdriverfile%.s}.o"

#exe file
    exefile="${sfile%.s}_as.ex"
    echo $exefile

#compile
    /home/mahdi/programs/simplescalar/bin/sslittle-na-sstrix-as -o  $obj $sfile
    /home/mahdi/programs/simplescalar/bin/sslittle-na-sstrix-as -o  $obj_driver $sdriverfile

#link
    /home/mahdi/programs/simplescalar/bin/sslittle-na-sstrix-ld -o $exefile $obj $obj_driver -L /home/mahdi/programs/simplescalar/sslittle-na-sstrix/lib -lc -L /home/mahdi/programs/simplescalar/lib/gcc-lib/sslittle-na-sstrix/2.7.2.3/ -lgcc



done

thanks for answers.

Answer 2

Obviously this is possible in shell. However many people find that the make utility is better for building software than shell scripts simply because of these dependencies. take a look at GNU Make. Its documentation contains numerous examples of what you're trying to do.

Answer 3

Caveat: Your tags "linux shell" do not specify a specific shell. POSIX sh, the standard specifying minimum required behavior for /bin/sh, does not support arrays; you should use a specific shell, such as bash or ksh, which does. To do this, you need to start your script with an appropriate shebang (such as #!/bin/bash instead of #!/bin/sh), and do any manual invocations with the correct shell (so bash -x myscript if you would otherwise use sh -x myscript... though if you've set the shebang correctly and have +x permissions, you can always just ./myscript)

---

# this is broken
FILES=PTscalar_1.0/mibenchforpt/security/sha/*.s

...does not create an array.

# this works in bash, ksh, and zsh
files=( PTscalar_1.0/mibenchforpt/security/sha/*.s )

does create an array, which can be expanded as "${files[@]}". So:

# this works in bash and ksh, and probably zsh
for file in "${files[@]}"; do
  ...
done

However, in this particular case, you don't have a reason to use an array at all:

# this works with absolutely any POSIX-compatible shell
for file in PTscalar_1.0/mibenchforpt/security/sha/*.s; do
  echo "$sfile"
  objectFile=${sfile%.s}.o
  exefile=${objectFile%.o}.ex

  simplescalar/bin/sslittle-na-sstrix-as -o "$objectFile" "$sfile"
done

Note a few corrections made in the above:

• The right-hand-side of assignments in with no literal whitespace in their syntax do not need to be quoted.
• All expansions (such as $objectFile) do need to be quoted, so, "$objectFile".
• ...yes, this does include echo; to test this, run s='*' and compare the output of echo $s to echo "$s".

---

To address the follow-up question you edited in:

ofiles=( PTscalar_1.0/mibenchforpt/security/sha/*.o )
simplescalar/bin/sslittle-na-sstrix-ld -o "$exefile" "${ofiles[0]}" "${ofiles[1]}"

...is a literal answer, but this would need to be edited if you had two or more outputs. Much better to do it this way instead:

ofiles=( PTscalar_1.0/mibenchforpt/security/sha/*.o )
simplescalar/bin/sslittle-na-sstrix-ld -o "$exefile" "${ofiles[@]}"