Shell Programming and Scripting

i have a flat file with around 700 columns . i want to break it into a flat file with say five columns like

col1,col2,col3,col4
col5,col6,col7,col8
col9...... ,col700

how can i do this

use a while read loop with IFS=","

Code:

awk -F"," '{ for(i=1;i<=NF;i=i+5){    print $i,$(i+1),$(i+2),$(i+3),$(i+4)  } }' file

I have a big file around 91 columns

when im running
awk -F"," '{ for(i=1;i<=NF;i=i+90){ print $i,",",$(i+1),",",.....$(i+90),$(i+91)} }'
bs > final

its giving me too many fields ....

---------- Post updated at 06:14 AM ---------- Previous update was at 06:11 AM ----------

bash-3.00$ awk '{print NF}' IRFEReconciliationReport-SPDM-AXJ_20090618_2.CSV
awk: record `Tracker ID#,RM Syste...' has too many fields

---------- Post updated at 06:38 AM ---------- Previous update was at 06:14 AM ----------

can we check for the 91st comma in the text line and insert a line feed ...

that should satisfy the need of the hour ..
1,2,3,4,..... ,90,91
92,93

can you please try with this :

awk -F"," '{ for(i=1;i<=NF;i=i+90) { for(j=0;j<90;j++) { printf "%s," , $(i+j) } printf "\n" } }'

Its giving the same error

awk: record `SPN 3, Revenue Clien...' has too many fields
record number 1