Shell Programming and Scripting

awk 'BEGIN{ FS = OFS = ","
l="13,2000,160,200,100,50,50,30,30,30,170"
split(l,len,",")
row=$1
split(f,field,",")
f="1,3,11"
split(c,col,",")
}
{
 for (i=1;i<=len,i++) {
  for (j in len) {
  if 
  if (length($(field[i])) = len[j] )

awk -F, ' { if(length($2)>6) $2=substr($2,1,6); if(length($4)>4) $4=substr($4,1,4); print; } ' OFS=, filename

awk -F, 'BEGIN {len="5,6,7,8";split(len,arr,",");}{for(i=1;i<=NF;i++){if(length($i)>arr[i])next}}1' input.csv

 
$ cat input.csv
this123,is,test,message
this,is,test,message
this,is,test,message
this,is,test,message123

 
$awk -F, 'BEGIN {len="5,6,7,8";split(len,arr,",");}{for(i=1;i<=NF;i++){if(length($i)>arr[i])next}}1' input.csv
this,is,test,message
this,is,test,message

 
$awk -F, 'BEGIN {len="5,0,0,8";split(len,arr,",");}{for(i=1;i<=NF;i++){if( arr[i]!=0 && length($i)>arr[i])next}}1'  input.csv
this,is,test,message
this,is,test,message

$ cat file
this123,is,test,mess
this,issdfd,test,mess
this,isdfsdsd,test,mes
this,isdsdddsd,test,message123

$ awk -F, 'length($2) <= 6 && length($4) <= 4' file
this123,is,test,mess
this,issdfd,test,mess

  nawk -F, 'BEGIN {len="5,6,7,8";split(len,arr,",");col="col1,col2,col3,col4";split(col,arr1,",");}{for(i=1;i<=NF;i++){if(length($i)>arr[i]) $i=substr($i,1,arr[i]); print${arr1[i]} next}}1' input.txt

input.txt
------------
 checking,the, lengthof, string

output.txt
----------
check,the, lengtho, string,Field col1,col3 exceeds the length

$ cat file
checking,the, lengthof, string
$ awk -F, 'BEGIN {split("5,6,7,8", len, ",");  OFS=","}
           {for (i=1; i<=NF; i++) if(length($i) > len[i]) {$i = substr($i, 1, len[i]); col[i]++; OA=1}}
           {printf "%s", $0;
            if (OA) {printf ", Fields ";
                     for (i=1; i<=NF; i++) {if (col[i]) printf "col%d ", i; col[i]=0;}
                     printf "exceed the length."
                    }
            printf "\n"; OA=0
           }
          ' file
 check,the, length, string, Fields col1 col3 exceed the length.