Using AWK to check a six column txt file - bash

Question

I am brand new to using Awk and I am running into a bit of a problem. I have multiple tab delimited text files that are made up of six columns. The column layout is:
col1=int
col2=float
col3=float
col4=int
col5=int
col6=DATE (yyyy-mm-dd)
The task at hand is to basically due a quality check on the text files to make sure that each column is that type. I also need to skip the first line since each tab delimited text file has has a header. So far this is what I have:
#!/bin/sh
awk < file1.txt -F\\t '
{(NR!=1)}
{if ($1 != int($1)||($2 != /[0-9]+\.[0-9]*/)||($3 != /[0-9]+\.[0-9]*/)||($4 != int($4)||($5 != int($5))print "Error At " NR; }
'
I am not required to use Awk, it is just that it seemed the most appropriate.
EDIT 1:
#!/bin/sh
awk < file1.txt -F\\t '
{if (NR!=1){
if ($1 != int($1)) print "Error col1 at " NR;
else if ($4 != int($4)) print "Error col4 at " NR;
else if ($5 != int($5)) print "Error col5 at " NR;
}
}
'
This seems to work fine so my questions now are:
1- How do I check for floats?
2- How do I run this over multiple files?

Answer 1

If this isn't what you want then edit your question to include some sample input and expected output:
awk '
function act_type(n, t) {
if (n ~ /^[0-9]{4}(-[0-9]{2}){2}$/) { t = "date" }
else if (n ~ /^-?[0-9]+\.[0-9]+$/) { t = "float" }
else if (n ~ /^-?[0-9]+$/) { t = "int" }
return t
}
BEGIN { split("int float float int int date",exp_type) }
{
for (i=1; i<=NF; i++) {
if (act_type(i) != exp_type[i]) {
print "Error col", i, "at", NR. "in", FILENAME | "cat>&2"
}
}
}
' file
massage the regexp to suit your data (i.e. if your ints can start with + and/or include ,s then include that in the regexp).

Answer 2

To test if a field is a number, you can check if
$1 + 0 == $1
This works because adding to a string converts it to zero, if it isn't a number.
To run a script on multiple files, you can just add them as extra parameters, e.g.
awk 'commands' file1 file2 file3