practice.sh

#!/bin/bash

# —————————————————————————————————————————————————————————————————— #
#                            Question 1.1                            #
#                                                                    #
# Called via: script.sh filename1 filename2 ...                      #
# If number of files < 2, print "Error" and quit                     #
# Print which of filename1 and filename2 has larger size             #
# —————————————————————————————————————————————————————————————————— #

for filename in $@; do
    if [[ -f "$filename" ]]; then bool=1
    else bool=0
    fi
done

if [[ bool -eq 1 ]]; then
    if [[ $# -lt 2 ]]; then echo -e "Use: LT3_A1.sh file_1 file_2"
    else
        size1="$(wc -c < "$1")"
        size2="$(wc -c < "$2")"

        if [[ "$size1" -gt "$size2" ]]; then
            echo -e "File_1 is bigger than File_2"
        elif [[ "$size1" -lt "$size2" ]]; then
            echo -e "File_2 is bigger than File_1"
        else
            echo -e "The two files are of the same size"
        fi
    fi
else
    echo -e "There is a problem with one of the files"
fi

# —————————————————————————————————————————————————————————————————— #
#                            Question 1.2                            #
#                                                                    #
# Print "Please enter a directory name" and read input               #
# If input is a directory, list all files and quit                   #
# Else, print "I said a directory" and repeat                        #
# Finally, print "You are hopeless" and quit                         #
# —————————————————————————————————————————————————————————————————— #

echo "Please enter a directory name "
read dirname

if [[ -d "$dirname" ]]; then; ls "$dirname"
else
    echo "I said a directory "
    read newdirname

    if [[ -d "$newdirname" ]]; then; ls "$newdirname"
    else; echo "You are hopeless."
    fi
fi

# —————————————————————————————————————————————————————————————————— #
#                            Question 1.3                            #
#                                                                    #
# Called via: script.sh filename string                              #
# If filename == "exit", quit program                                #
# If 'string' is / isn't in 'filename', print "Found" / "Not Found"; #
# Repeat in loop                                                     #
# —————————————————————————————————————————————————————————————————— #

while [[ $filename != "exit" ]]; do
    read filename
    read str

    if [[ -f "$filename" ]]; then
        if grep -q "$str" "$filename"; then; echo "Found"
        else; echo "Not Found"
        fi
    fi
done

# —————————————————————————————————————————————————————————————————— #
#                        Question 1.4 / 1.5                          #
#                                                                    #
# Format: (ddd) ddd-dddd                                             #
# Replace with: (xxx) ddd-dddd                                       #
# —————————————————————————————————————————————————————————————————— #

s/([0-9][0-9][0-9])/(xxx)/p


# —————————————————————————————————————————————————————————————————— #
#                            Question 2.3                            #
#                                                                    #
#  Format: last_name first_name course grade1 grade2 grade3          #
#  Filename is 'Ras.txt'                                             #
#  Called via: script.sh -G -R -C arg1 arg2                          #
#       For -G: -> arg1 := last_name, arg2 := first_name             #
#               -> prints grade avg, student name, course name       #
#                                                                    #
#       For -R: -> arg1 := course                                    #
#               -> prints list of students enrolled in course        #
#                                                                    #
#       For -C: -> arg1 := course                                    #
#               -> prints num of students in course                  #
# —————————————————————————————————————————————————————————————————— #

flag="$1"
arg1="$2"
arg2="$3"

if [[ "$flag" = "-G" ]]; then
    line=$(grep "$arg1 $arg2" Ras.txt)
    read -r last first course gr1 gr2 gr3 <<< "$line"
    let "sum = gr1 + gr2 + gr3"
    let "result = sum / 3"
    echo "-> $arg2 $arg1 has a $result average in $course"
fi

if [[ "$flag" = "-R" ]]; then
    echo "Enrolled in $arg1:"
    while read line; do
        read -r last first course gr1 gr2 gr3 <<< "$line"
        echo "-> $first ${last}"
    done <<< "$(grep "$arg1" Ras.txt)"
fi

if [[ "$flag" = "-C" ]]; then
    filename="$(grep "$arg1" Ras.txt)"
    num="$(wc -l <<< $filename)"
    echo "-> There are $((num+1)) students in $arg1"
fi