Single call to fgetcsv() exhausting large memory limit in PHP - memory

Question

I am trying to read two lines from a average-sized CSV (10 MB), the header and the first line. I have the memory limit for PHP set to 64 MB. Yet, on the second call to fgetcsv(), I get a memory exhausted error.
I've removed every unessential part of the script to debug, and traced memory usage step-by-step, and I still can't figure it out. Right after the first call, memory usage is under 1 MB, but at the second call, the memory exhaust error happens.
Here's the code:
<?php
function trace($msg) {
echo "<br>" . date("Y-m-d H:i:s") . " - " . memory_get_usage() . " bytes - {$msg}";
}
ini_set('display_errors', 'on');
error_reporting(E_ALL);
ob_implicit_flush(true);
trace("CSV Memory Limit test");
$path = "../data/uploaded/1405712684_base_leitores_july2014.csv";
trace("path = {$path}");
$fp = fopen($path, "r");
trace("file pointer opened");
trace("getting header...");
$header = fgetcsv($fp, 1024);
trace("header fetched");
var_dump($header);
trace("header displayed");
trace("fetching another line");
$l1 = fgetcsv($fp, 1024);
trace("line fetched");
var_dump($header);
trace("line displayed");
Here's the output:
2014-07-18 16:06:26 - 249544 bytes - CSV Memory Limit test
2014-07-18 16:06:26 - 249800 bytes - path = ../data/uploaded/1405712684_base_leitores_july2014.csv
2014-07-18 16:06:26 - 250840 bytes - file pointer opened
2014-07-18 16:06:26 - 250840 bytes - getting header...
2014-07-18 16:06:26 - 279280 bytes - header fetched
array (size=111)
0 => string 'razao social' (length=12)
1 => string 'Identificaao' (length=13)
2 => string 'save' (length=4)
3 => string 'id' (length=2)
4 => string 'categoria' (length=9)
5 => string 'nome fantasia' (length=13)
6 => string 'email' (length=5)
7 => string 'website' (length=7)
8 => string 'logradouro' (length=10)
9 => string 'endereco' (length=8)
10 => string 'numero' (length=6)
11 => string 'complemento' (length=11)
12 => string 'bairro' (length=6)
13 => string 'cidade' (length=6)
14 => string 'estado' (length=6)
15 => string 'cep' (length=3)
16 => string 'localidade' (length=10)
17 => string 'ddd' (length=3)
18 => string 'telefone' (length=8)
19 => string 'fax' (length=3)
20 => string 'contato' (length=7)
21 => string 'cargo' (length=5)
22 => string 'departamento' (length=12)
23 => string 'ramo de atividade' (length=17)
24 => string 'data de nascimento' (length=18)
25 => string 'especialidade' (length=13)
26 => string 'linha de atuacao' (length=16)
27 => string 'data de fundacao' (length=16)
28 => string 'classificacao de leitor' (length=23)
29 => string 'observacoes' (length=11)
30 => string 'is_protocolada' (length=14)
31 => string 'is_assinante' (length=12)
32 => string 'qtd_reclamacoes' (length=15)
33 => string 'error' (length=5)
34 => string 'errorReport' (length=11)
35 => string 'saved' (length=5)
36 => string 'onTrash' (length=7)
37 => string 'SugestAo de matEria' (length=19)
38 => string 'Campo2
#redacted#' (length=31)
39 => string '1' (length=1)
40 => string '0' (length=1)
41 => string '141657' (length=6)
42 => string '2000000041' (length=10)
43 => string '' (length=0)
44 => string '' (length=0)
45 => string '' (length=0)
46 => string 'RUA' (length=3)
47 => string '#redacted#' (length=15)
48 => string '#redacted#' (length=3)
49 => string '' (length=0)
50 => string 'JABAQUARA' (length=9)
51 => string 'PARI' (length=4)
52 => string 'SP' (length=2)
53 => string '#redacted#' (length=7)
54 => string '' (length=0)
55 => string '11' (length=2)
56 => string '#redacted#' (length=9)
57 => string '#redacted#' (length=9)
58 => string '#redacted#' (length=5)
59 => string '#redacted#' (length=12)
60 => string '' (length=0)
61 => string 'Centros Automotivos, Mec‰nicas e Oficinas - Leves' (length=49)
62 => string '' (length=0)
63 => string '' (length=0)
64 => string '' (length=0)
65 => string '' (length=0)
66 => string '' (length=0)
67 => string 'Centros Automotivos, MecAnicas e Oficinas - Leves ' (length=50)
68 => string 'N' (length=1)
69 => string '0' (length=1)
70 => string '0' (length=1)
71 => string '0' (length=1)
72 => string '' (length=0)
73 => string '1' (length=1)
74 => string '0' (length=1)
75 => string '' (length=0)
76 => string '
#redacted#' (length=16)
77 => string '2' (length=1)
78 => string '0' (length=1)
79 => string '228109' (length=6)
80 => string '2000000041' (length=10)
81 => string '0800 AUTOMOTIVE' (length=15)
82 => string '#redacted##hotmail.com' (length=32)
83 => string '' (length=0)
84 => string 'RUA' (length=3)
85 => string '#redacted#' (length=7)
86 => string '322' (length=3)
87 => string '' (length=0)
88 => string '' (length=0)
89 => string 'SAO PAULO' (length=9)
90 => string 'SP' (length=2)
91 => string '#redacted#' (length=7)
92 => string '' (length=0)
93 => string '11' (length=2)
94 => string '#redacted#' (length=9)
95 => string '#redacted#' (length=9)
96 => string '#redacted#' (length=40)
97 => string 'PROPRIETARIO' (length=12)
98 => string '' (length=0)
99 => string 'Centros Automotivos, Mec‰nicas e Oficinas - Leves' (length=49)
100 => string '' (length=0)
101 => string '' (length=0)
102 => string '' (length=0)
103 => string '' (length=0)
104 => string '' (length=0)
105 => string 'Centros Automotivos, MecAnicas e Oficinas - Leves ' (length=50)
106 => string '' (length=0)
107 => string '0' (length=1)
108 => string '0' (length=1)
109 => string '0' (length=1)
110 => string 'Registro criado' (length=15)
2014-07-18 16:06:26 - 287608 bytes - header displayed
2014-07-18 16:06:26 - 287608 bytes - fetching another line
( ! ) Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 72 bytes) in /home/lqdi/quantum.pranaeditora.com.br/sandbox/test_csv_read.php on line 25
Call Stack
# Time Memory Function Location
1 0.0011 249048 {main}( ) ../test_csv_read.php:0
2 0.0093 287520 fgetcsv ( ) ../test_csv_read.php:25
I am running php5-fpm (5.5.9) and nginx (1.4.6) on Ubuntu 14.04 LTS.

Answer 1

Finally, after a lot of headbanging, I found the problem: line endings.
Somewhy, Mac's Excel was exporting a CSV with a \r\n on the header and \n on all other lines. The header would come in nicely, but fgetcsv understood the second line was the entire document.
The fix was to add the following before fopen:
ini_set('auto_detect_line_endings',TRUE);
This will make fgetcsv detect line endings corrently when parsing the CSV file.