bash replacing characters within a variable

baks · 03-14-2007, 07:26 PM

Hi, can someone please help me PLEASE ?

I have a variable set as;
Word_used=bakar
The variable was then changed to a variable called $hidden “-----“ using the tr command.

My program accepts a single character entered by the user, checks it to see if exists in the word_used variable.

If the character exists in the word_used variable then the program should input that letter into the hidden word. For example if the letter k was entered by the user, the program should print --k--

i cannot get the program to enter the letter into the word if is correct.

The following is my code:

while [ $lives -ge 1 ]; do
counter1=1
echo
echo $hiddenword
echo "please enter a letter "
read input_letter # accepts the input
clear

if [ -z $input_letter ]; then # checks if nothing has been entered
echo "you have not entered anything"
echo "please enter a letter"
validation3=0 # resets loop
else

input_letter_length=`expr length $input_letter` # get length of input letter
if [ $input_letter_length -eq 1 ]; then

while [ $counter1 -le $word_length ];do # checks the letter input against the word_used
character=`echo $word_used | cut -b$counter1` # check each one at a time

if [ $input_letter = $character ];then

# THIS IS WHERE THE PROGRAM SHOULD ENTER THE LETTER INPUT BY THE USER INTO THE VARIABLE $HIDDENWORD. I NEED HELP ON HOW TO DO THIS.

fi
counter1=`expr $counter1 + 1` #continues loop until counter = length of word
done
# prints out the results for each letter
echo $hidden_word # prints out the hidden word with the correct letters
echo "you have entered the following letters $list_of_answers"
lives=`expr $lives - 1`
number_of_tries=`expr length $list_of_answers`
echo "you have had $number_of_tries tries"
echo "you have another $lives lives"
validation3=1 # this loop will contiue until lives has run out or incorrect data is entered
fi
fi

baks · 03-15-2007, 10:15 AM

Can anyone help ?

archtoad6 · 03-15-2007, 12:16 PM

In order to facilitate commentary, I have added line #'s to your code & put it in "Code" block below:

Code:

 1: while [ $lives -ge 1 ]; do             
 2:    counter1=1
 3:    echo
 4:    echo $hiddenword
 5:    echo "please enter a letter "
 6:    read input_letter                                        
 7:    # accepts the input
 8:    clear                                                    
 9:    
10:    # checks if nothing has been entered
11:    if [ -z $input_letter ]; then                             
12:       echo "you have not entered anything"                  
13:       echo "please enter a letter"
14:       validation3=0                                         
15:       # resets loop
16:    else                                   
17:       input_letter_length=`expr length $input_letter`       
18:       # get length of input letter
19:       if [ $input_letter_length -eq 1 ]; then
20: 
21:          # checks the letter input against the word_used
22:          while [ $counter1 -le $word_length ]; do  
23:             character=`echo $word_used | cut -b$counter1`   
24:             # check each one at a time
25:             if [ $input_letter = $character ]; then 
26: 
27:      # THIS IS WHERE THE PROGRAM SHOULD ENTER THE LETTER
28:      #  INPUT BY THE USER INTO THE VARIABLE $HIDDENWORD. 
29:      # I NEED HELP ON HOW TO DO THIS. 
30: 
31:             fi
32:             counter1=`expr $counter1 + 1`    
33:             #continues loop until counter = length of word
34:          done
35:          # prints out the results for each letter
36:          echo $hidden_word           
37:          # prints out the hidden word with the correct letters 
38:          echo "you have entered the following letters "   \
                  "$list_of_answers"
39:          lives=`expr $lives - 1`
40:          number_of_tries=`expr length $list_of_answers`
41:          echo "you have had $number_of_tries tries"
42:          echo "you have another $lives lives"
43:          validation3=1  
44:          #   this loop will contiue until lives has run out 
45:          #   or incorrect data is entered
46:       fi
47:    fi
48: done

In order to minimize horizontal scrolling in either of my browsers (Konqueror 3.3.2 & Opera 9); I put your original comments on the following line, changed the indents to 3 spaces, & broke l. 38 w/ a '\'.

I also added the missing closing "done" command.

I am preparing a long, & I hope helpful, reply.

baks · 03-15-2007, 07:32 PM

Thank you very much.

cfaj · 03-15-2007, 08:39 PM

Quote:

Originally Posted by baks

Hi, can someone please help me PLEASE ?

I have a variable set as;
Word_used=bakar
The variable was then changed to a variable called $hidden “-----“ using the tr command.

My program accepts a single character entered by the user, checks it to see if exists in the word_used variable.

If the character exists in the word_used variable then the program should input that letter into the hidden word. For example if the letter k was entered by the user, the program should print --k--

i cannot get the program to enter the letter into the word if is correct.

The following is my code:

while [ $lives -ge 1 ]; do

You haven't initialized $lives.

Quote:

counter1=1
echo
echo $hiddenword
echo "please enter a letter "
read input_letter # accepts the input
clear

if [ -z $input_letter ]; then # checks if nothing has been entered
echo "you have not entered anything"
echo "please enter a letter"
validation3=0 # resets loop
else

input_letter_length=`expr length $input_letter` # get length of input letter

POSIX shells (bash, ksh, ash, etc.) have a parameter expansion to get the length of a variable:
Code:
input_letter_length=${#input_letter}

Quote:

if [ $input_letter_length -eq 1 ]; then

while [ $counter1 -le $word_length ];do # checks the letter input against the word_used
character=`echo $word_used | cut -b$counter1` # check each one at a time

if [ $input_letter = $character ];then

# THIS IS WHERE THE PROGRAM SHOULD ENTER THE LETTER INPUT BY THE USER INTO THE VARIABLE $HIDDENWORD. I NEED HELP ON HOW TO DO THIS.

fi
counter1=`expr $counter1 + 1` #continues loop until counter = length of word
done

You don't need a counter; use temporary variables, extracting and removing the first character each time through the loop:

Code:

  word_right=$used_word
  hidden_right=$hidden
  hidden=
  while :
  do
    [ -z "$word_right" ] && break 
    right_temp=${word_right#?}
    word_letter=${word_right%"$right_temp"}
    hidden_temp=${hidden_right#?}
    hidden_letter=${hidden_right%"$hidden_temp"}
    if [ "$word_letter" = "$input_letter" ]
    then
      hidden_letter=$input_letter
    fi
    hidden=$hidden$hidden_letter
    word_right=$right_temp
    hidden_right=$hidden_temp
  done

Quote:

# prints out the results for each letter
echo $hidden_word # prints out the hidden word with the correct letters
echo "you have entered the following letters $list_of_answers"
lives=`expr $lives - 1`

In a POSIX shell, you do not need expr; the shell can do arithmetic:
Code:
lives=$(( $lives - 1 ))

Quote:

number_of_tries=`expr length $list_of_answers`
echo "you have had $number_of_tries tries"
echo "you have another $lives lives"
validation3=1 # this loop will contiue until lives has run out or incorrect data is entered
fi
fi

baks · 03-19-2007, 12:33 AM

Thank You greatly appreciated.