Add new file

the hatem homework

+السؤال الاول
+#!/bin/bash
+
+current_directory=$(pwd)
+
+for item in "$current_directory"/**/*.txt; do
+    if [[ -f "$item" ]]; then
+        sed -i 's/oldworld/newworld/g' "$item"
+    fi
+done
+
+
+
+========================================================================================
+script 2
+
+#!/bin/bash
+new_folder="$HOME/new_folder"
+mkdir -p "$new_folder"
+for letter in {a..z}; do
+    for number in {1..10}; do
+        filename="file${number}_${letter}"
+        touch "$new_folder/$filename"
+    done
+done
+for file in "$new_folder"/*_x; do
+    echo "Hello Linux" > "$file"
+done
+for letter in {a..z}; do
+    folder="$new_folder/$letter"
+    mkdir -p "$folder"
+    mv "$new_folder"/*_$letter "$folder"
+done
+find "$new_folder" -type f \( -name "*3*" -o -name "*4*" \) -delete
+
+========================================================================================
+#!/bin/bash
+# alive2.sh
+# Checks to see if a range of hosts are alive
+
+start_ip=$(echo "$1" | cut -d- -f1)
+end_ip=$(echo "$1" | cut -d- -f2)
+
+network_prefix=$(echo "$start_ip" | cut -d. -f1-3)
+
+start_range=$(echo "$start_ip" | cut -d. -f4)
+end_range=$(echo "$end_ip" | cut -d. -f4)
+
+
+if (( end_range >= start_range )); then
+    for ((n=start_range; n<=end_range; n++)); do
+        host="$network_prefix.$n"
+        ping -c2 "$host" &> /dev/null
+        if [ $? = 0 ]; then
+            echo "$host is UP"
+        else
+            echo "$host is DOWN"
+        fi
+    done
+else
+    echo "Invalid range. The end range is smaller than the start range."
+fi