Asked  7 Months ago    Answers:  5   Viewed   64 times

I need to write a script that starts my program with different arguments, but I'm new to Bash. I start my program with:

./MyProgram.exe Data/data1.txt [Logs/data1_Log.txt].

Here is the pseudocode for what I want to do:

for each filename in /Data do
  for int i = 0, i = 3, i++
    ./MyProgram.exe Data/filename.txt Logs/filename_Log{i}.txt
  end for
end for

So I'm really puzzled how to create second argument from the first one, so it looks like dataABCD_Log1.txt and start my program.



A couple of notes first: when you use Data/data1.txt as an argument, should it really be /Data/data1.txt (with a leading slash)? Also, should the outer loop scan only for .txt files, or all files in /Data? Here's an answer, assuming /Data/data1.txt and .txt files only:

for filename in /Data/*.txt; do
    for ((i=0; i<=3; i++)); do
        ./MyProgram.exe "$filename" "Logs/$(basename "$filename" .txt)_Log$i.txt"


  • /Data/*.txt expands to the paths of the text files in /Data (including the /Data/ part)
  • $( ... ) runs a shell command and inserts its output at that point in the command line
  • basename somepath .txt outputs the base part of somepath, with .txt removed from the end (e.g. /Data/file.txt -> file)

If you needed to run MyProgram with Data/file.txt instead of /Data/file.txt, use "${filename#/}" to remove the leading slash. On the other hand, if it's really Data not /Data you want to scan, just use for filename in Data/*.txt.

Tuesday, June 1, 2021
answered 7 Months ago

If you want to use one variable and perform and action with it, you just need to use one loop:

for file in 4 5 6 7 8
   paste "${file}_1" "${file}_2"

This will do

paste 4_1 4_2
paste 5_1 5_2
Tuesday, June 1, 2021
answered 7 Months ago
readarray -d '' entries < <(printf '%s' *.fas | sort -zV)
for entry in "${entries[@]}"; do
  # do something with $entry

where printf '%s' *.fas yields a NUL separated list of directory entries with the extension .fas, and sort -zV sorts them in natural order.

Note that you need GNU sort installed in order for this to work.

Wednesday, June 23, 2021
answered 6 Months ago

Adding *.jar to the Project is done by using build.gradle file:

  • If you want to add a jar file to the project, Facebook had already done on your behalf!
    Just add a libs folder into the android/app directory of the project with your jar file and enjoy!

enter image description here

  • If you want to add a jar file to a native-module then add the line of compile fileTree(dir: "libs", include: ["*.jar"]) into the dependencies part of build.gradle file of the native-module.


After I added okhttp-3.4.1.jar file into the lib folder, I also add that package name to the dependencies part as the following:

dependencies {
    compile fileTree(dir: "libs", include: ["*.jar"])
    compile 'com.facebook.react:react-native:0.19.+'


If I need another package -that is found in Maven repo- I have to add into dependencies block as following (for instance I wanna add fresco):

dependencies {
    compile 'com.facebook.fresco:fresco:1.9.0'

Then Gradle will find and install dependency library Fresco for me.

Usually, every Android project has already Maven repo. configurations in build.gradle file which is found in top of folder of the project. For example:

allprojects {
    repositories {
        maven {
            url ""


(I have never tried this however it should be worked)
If I have an drawee-debug.aar file I can add it into my project by putting it into lib folder as directed on Example-1 then I have to change fileTree line as following:

compile fileTree(dir: "libs", include: ["*.jar", "*.aar"])  // "*.aar" is added


(alternate way of Example-3)
If I have an drawee-debug.aar file also I can add it into my project by putting it into lib folder as directed on Example-1 then I have to change and add some lines as following:

dependencies {
    compile (name:'drawee-debug', ext:'aar')

allprojects {
    repositories {
        flatDir {
            dirs 'libs', './libs'

In this way, libs directory is defined in allprojects folder and aar file specified in dependencies block, like othe examples.

Note that after Gradle v3.0.1 implementation is used instead compile key word.


Monday, August 2, 2021
answered 4 Months ago

Something like this would do:

xargs cat <filenames.txt

The xargs program reads its standard input, and for each line of input runs the cat program with the input lines as argument(s).

If you really want to do this in a loop, you can:

for fn in `cat filenames.txt`; do
    echo "the next file is $fn"
    cat $fn
Saturday, August 7, 2021
answered 4 Months ago
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