Bash script to find and replace texts inside a file

UpdateFile.sh

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#### Function to find and replace a text inside file using bash
updateLateCommandURLInPreseedFile(){
    echo "[INFO]:: Updating late command url in pressed.cfg file**************"
    echo ""
    cat preseed.cfg | sed  's_${IPADDR}_'"$IP"'_g' > temp.cfg
    cat temp.cfg > preseed.cfg
    rm temp.cfg
    echo "[INFO]:: Successfully substituted IP address of late command server****************"
}

#### Calling function
updateLateCommandURLInPreseedFile

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