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Bash : how do i check the user input and make sure is only chracter or only number ?

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Top Forums Shell Programming and Scripting Bash : how do i check the user input and make sure is only chracter or only number ?
# 1  
Old 09-07-2008
Bash : how do i check the user input and make sure is only chracter or only number ?
Bash : how do i check the user input and make sure is only character or only number ?
# 2  
Old 09-07-2008
one way
Code:
echo "$user_input" | tr -dc '[:digit:]' | read check_it
if [[ ${#check_it} -eq 0 ]] ; then
     echo 'all numbers'
fi
echo "$user_input" | tr -dc '[:alpha:]' | read check_it
if [[ ${#check_it} -eq 0 ]] ; then
     echo 'all alphabetic characters'
fi

# 3  
Old 09-07-2008
if i only want to check the first digit wheter is a number "0" or not .
how to do it
# 4  
Old 09-07-2008
Code:
echo "$user_input | grep -q '^0' && echo 'first character is zero'

# 5  
Old 09-07-2008
grep for ^0

Code:
grep "^0"

# 6  
Old 09-07-2008
i want check the user input and make sure only
alphabetic characters and spaces how i can do that?

"enter something"
read input

i want check the $input . how ?
# 7  
Old 09-07-2008
Code:
case $input in
  *[!0-9]*) case $input in
    *[! A-Za-z]*) echo not all numbers or all spaces+alphabetics;;
    *) echo all spaces or alphabetics;;
  esac;;
  *) echo all numbers;;
esac
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