Maximum length of a string Post: 302963037

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Top Forums Shell Programming and Scripting Maximum length of a string Post 302963037 by durden_tyler on Tuesday 22nd of December 2015 03:14:02 PM

12-22-2015

Registered User

Do you want to find the length of each line in a file?
Here's a complete example with a few methods to find the length:

Code:

$ 
$ cat data.log
cadena1
cadenados
cadenatercera
cadenatercera
beer
$ 
$ cat line_length.sh
#!/bin/bash
FILE="data.log"
while read linea
do
    largo=$(echo $linea | awk '{print length($0)}')   # One way to find length
    len=${#linea}                                     # And another way to find length
    len1=$(awk -v L=$linea 'BEGIN{print length(L)}')  # And another way to find length
    len2=$(expr length $linea)                        # And another way to find length
    len3=$(echo -n $linea | wc -c)                    # And another way to find length
    echo $largo,$len,$len1,$len2,$len3
done < $FILE
$ 
$ . line_length.sh
7,7,7,7,7
9,9,9,9,9
13,13,13,13,13
13,13,13,13,13
4,4,4,4,4
$ 
$

The title of the post suggests that maybe you want to find the maximum length of a line in a file.
Do you want to find out the length of the longest line in your file?
In that case, a complete example is posted below:

Code:

$ 
$ cat data.log
cadena1
cadenados
cadenatercera
cadenatercera
beer
$ 
$ cat max_line_length.sh
#!/bin/bash
MAX=0
FILE="data.log"
while read linea
do
    len=${#linea}
    if [ $len -gt $MAX ]
    then
        MAX=$len
    fi
done < $FILE
echo "Max length is $MAX"
$ 
$ . max_line_length.sh
Max length is 13
$ 
$

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LEARN ABOUT PHP

pg_field_name

PG_FIELD_NAME(3)														  PG_FIELD_NAME(3)

pg_field_name - Returns the name of a field

SYNOPSIS

       string pg_field_name (resource  $result, int  $field_number)

DESCRIPTION

       pg_field_name(3)  returns the name of the field occupying the given $field_number in the given PostgreSQL $result resource. Field numbering
       starts from 0.

       Note

	       This function used to be called pg_fieldname(3).

PARAMETERS

	      o $result
		- PostgreSQL query result resource, returned by pg_query(3), pg_query_params(3) or pg_execute(3) (among others).

	      o $field_number
		- Field number, starting from 0.

RETURN VALUES

	The field name, or FALSE on error.

EXAMPLES

       Example #1

	      Getting information about fields

	      <?php
		$dbconn = pg_connect("dbname=publisher") or die("Could not connect");

		$res = pg_query($dbconn, "select * from authors where author = 'Orwell'");
		$i = pg_num_fields($res);
		for ($j = 0; $j < $i; $j++) {
		    echo "column $j
";
		    $fieldname = pg_field_name($res, $j);
		    echo "fieldname: $fieldname
";
		    echo "printed length: " . pg_field_prtlen($res, $fieldname) . " characters
";
		    echo "storage length: " . pg_field_size($res, $j) . " bytes
";
		    echo "field type: " . pg_field_type($res, $j) . " 

";
		}
	      ?>

	      The above example will output:

	      column 0
	      fieldname: author
	      printed length: 6 characters
	      storage length: -1 bytes
	      field type: varchar

	      column 1
	      fieldname: year
	      printed length: 4 characters
	      storage length: 2 bytes
	      field type: int2

	      column 2
	      fieldname: title
	      printed length: 24 characters
	      storage length: -1 bytes
	      field type: varchar

SEE ALSO

       pg_field_num(3).

PHP Documentation Group 													  PG_FIELD_NAME(3)