there is something wrong with "trap INT"
the code is :
##############´úÂëÈçÏ£¬the red is wrong###############
#!/bin/sh

trap 'rm -f /tmp/my_tmp_file_$$' INT
echo creating file /tmp/my_tmp_file_$$
date > /tmp/my_tmp_file_$$

echo "Press interrupt (Ctrl-C) to interrupt...."
while [ -f /tmp/my_tmp_file_$$ ]; do
echo File exists
sleep 1
done
echo The file no longer exists

trap INT
echo creating file /tmp/my_tmp_file_$$
date > /tmp/my_tmp_file_$$

echo "Press interrupt (Ctrl-C) to interrupt...."
while [ -f /tmp/my_tmp_file_$$ ]; do
echo File exists
sleep 1
done

echo We never get here

exit 0



##########################

i change "trap INT" to "trap 2" and it right.why???

###########the answers#############
# ./_trap
creating file /tmp/my_tmp_file_7456
Press interrupt (Ctrl-C) to interrupt....
File exists
File exists
The file no longer exists
trap: usage: trap [-lp] [arg signal_spec ...]
##############################

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###########Ö´Ðнá¹û#############
# ./_trap
creating file /tmp/my_tmp_file_7456
Press interrupt (Ctrl-C) to interrupt....
File exists
File exists
The file no longer exists
trap: usage: trap [-lp] [arg signal_spec ...]
##############################


##############´úÂëÈçÏ£¬ºìÉ«µÄΪ Ð޸ĵĵط½###############
#!/bin/sh

trap 'rm -f /tmp/my_tmp_file_$$' INT
echo creating file /tmp/my_tmp_file_$$
date > /tmp/my_tmp_file_$$

echo "Press interrupt (Ctrl-C) to interrupt...."
while [ -f /tmp/my_tmp_file_$$ ]; do
echo File exists
sleep 1
done
echo The file no longer exists

trap INT
echo creating file /tmp/my_tmp_file_$$
date > /tmp/my_tmp_file_$$

echo "Press interrupt (Ctrl-C) to interrupt...."
while [ -f /tmp/my_tmp_file_$$ ]; do
echo File exists
sleep 1
done

echo We never get here

exit 0



##########################