adding an html comment at the top in bash

Question

Hello i have to write a short program to take in an input and add it to the top of file and add a timestamp into the bottom of the file also in an html comment. just a little confused how to do this

echo "What would you like to add to the top of the file
read x
cat $x >> File1

But this is to add this at the end of the file? Thanks in advance!

possible duplicate http://stackoverflow.com/a/9533736/975114 — Amit Verma, Mar 05 '14 at 21:33

score 0 · Answer 1 · answered Mar 05 '14 at 21:35

0

#!/bin/bash

# No go, if file not existant
test -f "$1" || exit 1

# Need a temp filename. Yes, this is racy.
test -f "$1.tmp" && exit 1

# Read text
echo 'What would you like to add to the top of the file?'
read COMMENT

# Exit on empty text
test -z "$COMMENT" && exit 1

# Write header
mv "$1" "$1.tmp"
echo -n "<!-- $COMMENT -->" > "$1"

# Write content
cat "$1.tmp" >> "$1"
rm "$1.tmp"

# Write footer
TS=$(date)
echo -e "\n<!-- $TS -->" >> "$1"

answered Mar 05 '14 at 21:35

Eugen Rieck

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Use `mktemp` to avoid being racy. – Stephen P Mar 05 '14 at 22:01
Ofcourse I know. Point is, that from the OQ i guessed, this would be no problem and the example is much more readable this way. – Eugen Rieck Mar 05 '14 at 22:16

score 0 · Answer 2 · answered Mar 05 '14 at 21:40

read -p 'What would you like to add at the top of the file?' header
cat - "$oldfile" <<< "$header" > "$newfile"

or

printf '%s\n' 'What would you like to add at the top of the file?' \
  '(hit ctrl-c on newline to commit, or ctrl-c to abort.)'
cat - "$oldfile" > "$newfile"

score 0 · Answer 3 · answered Mar 05 '14 at 22:16

0

Here's where the shell's grouping construct comes in handy:

comment () { echo "<!-- $* -->"; }
read -p "what?" top
{ comment "$top"; cat $htmlfile; comment $(date); } > $htmlfile.new

answered Mar 05 '14 at 22:16

glenn jackman

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score 0 · Answer 4 · answered Mar 12 '14 at 08:59

0

echo "What would you like to add to the top of the file
read x
sed -i '1s/^/$x/' file

answered Mar 12 '14 at 08:59

iamsrijon

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adding an html comment at the top in bash

4 Answers4