zsh process file script - loops

Question

I'm attempting to have this process a number of files but I don't want it in a look so I don't have to monitor it.
#!/usr/local/bin/zsh
X=${1-20}
for (( N=1; N<=X; N++ )); do
for p in *.xml; do
curl -X POST -H "Content-Type:application/xml" -d "#${p}" "https://url /postAPI" > "post_${p}"
sleep 1
done
done
When doing ./work.sh 5 this loops forever!
What's causing infinate loop?
Edit Based on a comment below
/tmp/tmp.KeFYeM9Z % ls -l
total 4
-rwxr-xr-x 1 naes wheel 218 Nov 20 14:42 work.sh
#!/usr/local/bin/zsh
X=${1-20}
for (( N=1; N<=X; N++ )); do
for p in /tmp/tmp.u6RnKaJ3/*.xml; do
curl -X POST -H "Content-Type:application/xml" -d "#${p}" "https://url /postAPI"
sleep 1
done
done
This still continues the infinite loop
This doesn't:
% cat work1.sh
#!/usr/local/bin/zsh
X=${1-20}
for (( N=1; N<=X; N++ )); do
date
sleep 1
done
% ./work1.sh 5
Thu Nov 20 15:22:27 PST 2014
Thu Nov 20 15:22:28 PST 2014
Thu Nov 20 15:22:29 PST 2014
Thu Nov 20 15:22:30 PST 2014
Thu Nov 20 15:22:31 PST 2014
What in my loop causes the infinite?

Answer 1

You are writing to the same directory you are reading from. So while reading the xml files you are writing xml files making it essentially loop forever. Although it's not really an infinite loop, it's a very large one.
Let's say you have 10 files, in that case you'll have this result:
N=1: |p| = 100
N=2: |p| = 200
N=3: |p| = 400
N=4: |p| = 800
N=5: |p| = 1600
So... it groes quite fast.
This should do the trick:
#!/usr/local/bin/zsh
X=${1-20}
OUTPUT_DIR=/tmp/output/
mkdir -p $OUTPUT_DIR
cd /tmp/tmp.u6RnKaJ3
for (( N=1; N<=X; N++ )); do
echo "Attempt $N"
for p in *.xml; do
curl -X POST -H "Content-Type:application/xml" -d "#${p}" "https://url /postAPI" > "${OUTPUT_DIR}post_${p}"
sleep 1
done
done