Update README.md

README.md

 HOMEWORK LINUX
+
+EX1:
+
+script :
+
+#!/bin/bash
+
+if [ "$#" -ne 3 ]; then
+    echo "Usage: $0 oldword newword extension"
+    exit 1
+fi
+
+oldword=$1
+newword=$2
+extension=$3
+
+find . -type f -name "*.$extension" -exec sed -i "s/$oldword/$newword/g" {} +
+
+echo "All occurrences of '$oldword' have been replaced with '$newword' in all .$extension files."
+
+in terminal :
+
+chmod +x name_of_script
+./name_of_script  oldword newword txt
+
+
+
+EX2 :
+in teminal :
+
+a-
+
+mkdir ~/new_folder
+cd ~/new_folder
+
+b-
+
+for i in {1..10}; do for j in {a..z}; do touch "file${i}_${j}"; done; done
+
+c-
+
+for i in {1..10}; do echo "Hello Linux" > "file${i}_x"; done
+
+d-
+
+for letter in {a..z}; do
+    mkdir -p "$letter"
+    mv *_"$letter" "$letter"/
+done
+
+
+e-
+
+
+find . -type f \( -name '*3*' -o -name '*4*' \) -delete
+
+
+
+
+EX3 :
+
+
+in script :
+#!/bin/bash
+# alive2.sh
+# Checks to see if a range of hosts are alive
+# Usage: alive2.sh 192.168.1.7-192.168.1.123
+
+# Function to display usage
+usage() {
+    echo "Usage: $0 start_ip-end_ip"
+    exit 1
+}
+# Check if the correct number of arguments are provided
+if [ "$#" -ne 1 ]; then
+    usage
+fi
+
+# Validate IP range format
+if [[ ! "$1" =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}-([0-9]{1,3}\.){3}[0-9]{1,3}$ ]]; then
+    echo "Invalid IP range format."
+    usage
+fi
+start_ip=${1%-*}
+end_ip=${1#*-}
+
+# Convert IP to integer
+ip_to_int() {
+    local a b c d
+    IFS=. read -r a b c d <<< "$1"
+    echo $((a * 256 ** 3 + b * 256 ** 2 + c * 256 + d))
+}
+int_to_ip() {
+    local ip dec=$1
+    for e in {3..0}; do
+        ((octet = dec / (256 ** e)))
+        ((dec -= octet * 256 ** e))
+        ip+=$octet.
+    done
+    echo "${ip%.}"
+}
+if [ "$(ip_to_int "$start_ip")" -gt "$(ip_to_int "$end_ip")" ]; then
+    echo "Start IP must be less than or equal to end IP."
+    exit 1
+fi
+
+# Iterate through IP addresses
+current_ip=$(ip_to_int "$start_ip")
+end_ip_int=$(ip_to_int "$end_ip")
+while [ "$current_ip" -le "$end_ip_int" ]; do
+    host=$(int_to_ip "$current_ip")
+    ping -c2 "$host" &> /dev/null
+    if [ $? -eq 0 ]; then
+        echo "$host is UP"
+    else
+        echo "$host is DOWN"
+    fi
+    ((current_ip++))
+done
+
+
+
+in terminal :
+cd /path/to/your/directory
+
+git init
+
+git add name_of_script
+
+git commit -m "Initial commit of name_of_script"
+
+git remote add origin https://github.com/mohammad/network-check.git
+
+git push -u origin master
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