Shell Programming and Scripting

Hi all,

Can any one tell the script to print a line with one bye one character or word..

Ex: Hi every one. How are you all ....

I want to print like...

First it has to print H then sleep some time and i and again sleep and e ... etc

OR

Hi wait some time and every ..... etc


Thanks in advance...

Code:

s='Hi every one. How are you all ....'

# char by char
while [ ${#s} -gt 0 ]; do
  printf '%s\n' "${s%${s#?}}"
  s=${s#?}
  sleep 2
done  

s='Hi every one. How are you all ....'

# word by word
# the follwoing command will
# reset any positional parameters
# and it does not work if shell word
# splitting is disabled (zsh disables it
# by default)

set -- $s

for w; do
  printf '%s\n' "$w"
  sleep 2
done

Hi,

Code:

nawk -F' ' '{for(i=1;i<=NF;i++){print $i;system("sleep 1");}}' File_name

Cheers,
Ranga

Another one char-by-char, bash specific:

Code:

s='Hi every one. How are you all ....'
while read -rn1;do printf '%s\n' "$REPLY"; sleep 2; done<<<"$s"

Hello, radoulov:

For the sake of novice learners, I am pointing out two spots in your suggestions which make them unsuitable for handling miscellaneous text.

${s%${s#?}}: If there's an asterisk in the text, when the character preceding the asterisk should be output, the asterisk will be printed as well. For example, if the line is '2*3=6', when trying to output 2 by removing '*3=6' using the % shortest suffix removal operator, the asterisk will be forced to match nothing. Output in this instance will be '2*' instead of just '2'.

set -- $s: In the second solution you cannot quote $s since it depends on field splitting. Unfortunately, that also leaves the expansion open to file globbing, leaving the approach vulnerable a few metacharacters. I suppose this could be worked around by toggling a noglob option.

You are probably aware of these things, but, as I said, I mention them mostly for novices unaware of the corner cases.

Regards,
Alister

Very good points! Thank you Alister!

If I'm not missing something, this should work around the first issue:

Code:

s='2*3=6'
while [ ${#s} -gt 0 ]; do   
  printf '%.1s\n' "$s"   
  s=${s#?}  
done

As you pointed out, set -f should be added for the second one (and special care should be taken for the IFS characters anyway, but I hope words with embedded tabs (HT/011) are not supposed to be present and the current IFS contains its default values).

I agree.

A marginally simpler way of achieving the same result:

Code:

s='2*3=6'
while [ -n "$s" ]; do   
  printf '%c\n' "$s"   
  s=${s#?}  
done

Regards,
Alister