prepend

伯克利做的SFTP安全文件传输协议

#! /bin/csh -f
# script to prepend a single line of text to a text file

if ( "$2" == "" ) then
  echo "usage: $0 filename line-to-prepend"
  exit
endif

# grab filename
set fname = $1

# shift arguments, so $* can refer to everything
shift

# if file doesn't exist, just create it and bail
if ( -e $fname ) then
  # it exists
else
  echo $* > $fname
  exit
endif

# copy the existing file to a temporary file ($$ is pid)
set tmp = /tmp/prepend.$$
mv $fname $tmp

# write the first line
echo $* > $fname

# append the remainder of the original file
cat $tmp >> $fname

# remove the temporary file
rm $tmp