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Introducción a la ciencia de la computación

Detalles Bibliográficos
Autor Principal:	Zwass, Vladimir
Formato:	Libro
Lengua:	español
Datos de publicación:	México : Compañía Editorial Continental, 1985
Edición:	1a ed.
Series:	Serie de compendios científicos El tutor del estudiante
Temas:	INFORMÁTICA
Acceso en línea:	Consultar en el Cátalogo
Descripción Física:	284 p. : il. ; 22 cm.
ISBN:	9682605202

Tabla de Contenidos:

Las computadoras y su uso en la solución de problemas
Fundamentos de programación
Conceptos de los sistemas de cómputo
Ap. A. Representación de los datos numéricos en la memoria de la computadora
Ap. B. Códigos de carateres
Ap. C. Algebra booleana y lógica de computación.

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Whoops \ Exception \ ErrorException (E_WARNING)

fopen(/tmp/vufind_sessions/sess_9kipjs6j7vg6s33an28pvopni5): Failed to open stream: No space left on device

Whoops\Exception\ErrorException thrown with message "fopen(/tmp/vufind_sessions/sess_9kipjs6j7vg6s33an28pvopni5): Failed to open stream: No space left on device" Stacktrace: #5 Whoops\Exception\ErrorException in /usr/local/vufind/module/VuFind/src/VuFind/Session/File.php:158 #4 fopen in /usr/local/vufind/module/VuFind/src/VuFind/Session/File.php:158 #3 VuFind\Session\File:saveSession in /usr/local/vufind/module/VuFind/src/VuFind/Session/AbstractBase.php:193 #2 VuFind\Session\AbstractBase:write in [internal]:0 #1 session_write_close in /usr/local/vufind/vendor/laminas/laminas-session/src/SessionManager.php:242 #0 Laminas\Session\SessionManager:writeClose in [internal]:0

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5

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…/module/VuFind/src/VuFind/Session/File.php158

4

fopen

…/module/VuFind/src/VuFind/Session/File.php158

3

VuFind\Session\File saveSession

…/module/VuFind/src/VuFind/Session/AbstractBase.php193

2

VuFind\Session\AbstractBase write

[internal]0

1

session_write_close

…/vendor/laminas/laminas-session/src/SessionManager.php242

0

Laminas\Session\SessionManager writeClose

[internal]0

Open: /usr/local/vufind/module/VuFind/src/VuFind/Session/File.php

        foreach (glob($this->path . '/sess_*') as $filename) {
            if (filemtime($filename) + $maxlifetime < time()) {
                unlink($filename);
            }
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        return true;
    }
 
    /**
     * A function that is called internally when session data is to be saved.
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     *
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    protected function saveSession($sessId, $data): bool
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                // Make sure that there's no trailing data by truncating the file to
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                ftruncate($handle, strlen($data));
                fflush($handle);
                flock($handle, LOCK_UN);
            }
            fclose($handle);
            if ($return !== false) {
                return true;
            }
        }
        // If we got this far, something went wrong with the file output...
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Arguments

              "fopen(/tmp/vufind_sessions/sess_9kipjs6j7vg6s33an28pvopni5): Failed to open stream: No space left on device"

          

Open: /usr/local/vufind/module/VuFind/src/VuFind/Session/File.php

        foreach (glob($this->path . '/sess_*') as $filename) {
            if (filemtime($filename) + $maxlifetime < time()) {
                unlink($filename);
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        return true;
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    /**
     * A function that is called internally when session data is to be saved.
     *
     * @param string $sessId The current session ID
     * @param string $data   The session data to write
     *
     * @return bool
     */
    protected function saveSession($sessId, $data): bool
    {
        $sessFile = $this->path . '/sess_' . $sessId;
        if ($handle = fopen($sessFile, 'w')) {
            $return = false;
            // Lock the file for exclusive access to avoid issues with multiple
            // processes writing session simultaneously:
            if (flock($handle, LOCK_EX)) {
                $return = fwrite($handle, $data);
                // Make sure that there's no trailing data by truncating the file to
                // the correct length:
                ftruncate($handle, strlen($data));
                fflush($handle);
                flock($handle, LOCK_UN);
            }
            fclose($handle);
            if ($return !== false) {
                return true;
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        // If we got this far, something went wrong with the file output...
        // It is tempting to throw an exception here, but this code is called
        // outside of the context of exception handling, so all we can do is
        // echo a message.

Open: /usr/local/vufind/module/VuFind/src/VuFind/Session/AbstractBase.php

        // Anecdotal testing Today and Yesterday seems to indicate destroy()
        //   is called by the garbage collector and everything is good.
        // Something to keep in mind though.
        return true;
    }
 
    /**
     * Write function that is called when session data is to be saved.
     *
     * @param string $sessId The current session ID
     * @param string $data   The session data to write
     *
     * @return bool
     */
    public function write($sessId, $data): bool
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        if ($this->writesDisabled) {
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    /**
     * A function that is called internally when session data is to be saved.
     *
     * @param string $sessId The current session ID
     * @param string $data   The session data to write
     *
     * @return bool
     */
    abstract protected function saveSession($sessId, $data): bool;
}

Open: [internal]

Open: /usr/local/vufind/vendor/laminas/laminas-session/src/SessionManager.php

     *
     * @return void
     */
    public function writeClose()
    {
        // The assumption is that we're using PHP's ext/session.
        // session_write_close() will actually overwrite $_SESSION with an
        // empty array on completion -- which leads to a mismatch between what
        // is in the storage object and $_SESSION. To get around this, we
        // temporarily reset $_SESSION to an array, and then re-link it to
        // the storage object.
        //
        // Additionally, while you _can_ write to $_SESSION following a
        // session_write_close() operation, no changes made to it will be
        // flushed to the session handler. As such, we now mark the storage
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            $_SESSION = $storage->toArray(true);
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            $storage->fromArray($_SESSION);
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    /**
     * Attempt to set the session name
     *
     * If the session has already been started, or if the name provided fails
     * validation, an exception will be raised.
     *
     * @param  string $name
     * @return SessionManager
     * @throws Exception\InvalidArgumentException
     */
    public function setName($name)
    {
        if ($this->sessionExists()) {
            throw new Exception\InvalidArgumentException(
                'Cannot set session name after a session has already started'

Open: [internal]

Environment & details:

GET Data

Key	Value
print	"1"

POST Data empty

Files empty

Cookies

Key	Value
language	"es"
VUFIND_SESSION	"9kipjs6j7vg6s33an28pvopni5"
ui	"standard"

Session

Key	Value
__Laminas	array:2 [`"_REQUEST_ACCESS_TIME" => 1749773744.6356 "_VALID" => array:1 [ "Laminas\Session\Validator\Id" => "9kipjs6j7vg6s33an28pvopni5" ]`]
SessionState	Laminas\Stdlib\ArrayObject {#906}
FlashMessenger	Laminas\Stdlib\ArrayObject {#1507}
SessionHelper	Laminas\Stdlib\ArrayObject {#1676}

Server/Request Data

Key	Value
REDIRECT_SCRIPT_URL	"/Record/dif.50951/TOC"
REDIRECT_SCRIPT_URI	"http://vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar/Record/dif.50951/TOC"
REDIRECT_VUFIND_ENV	"development"
REDIRECT_VUFIND_LOCAL_DIR	"/usr/local/vufind/local"
REDIRECT_STATUS	"200"
SCRIPT_URL	"/Record/dif.50951/TOC"
SCRIPT_URI	"http://vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar/Record/dif.50951/TOC"
VUFIND_ENV	"development"
VUFIND_LOCAL_DIR	"/usr/local/vufind/local"
HTTP_ACCEPT	"/"
HTTP_USER_AGENT	"Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)"
HTTP_COOKIE	"language=es; VUFIND_SESSION=9kipjs6j7vg6s33an28pvopni5; ui=standard"
HTTP_ACCEPT_ENCODING	"gzip, br, zstd, deflate"
HTTP_HOST	"vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar"
HTTP_VIA	"1.1 squid-proxy-5b5d847c96-zgj6k (squid/6.10)"
HTTP_X_FORWARDED_FOR	"10.3.91.56"
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REMOTE_PORT	"33950"
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GATEWAY_INTERFACE	"CGI/1.1"
SERVER_PROTOCOL	"HTTP/1.1"
REQUEST_METHOD	"GET"
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REQUEST_URI	"/Record/dif.50951/TOC?print=1"
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PHP_SELF	"/index.php"
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Environment Variables empty

Registered Handlers

0. Whoops\Handler\PrettyPageHandler

Cannot write session to /tmp/vufind_sessions/sess_9kipjs6j7vg6s33an28pvopni5 Whoops! There was an error.

Whoops \ Exception \ ErrorException (E_WARNING)

session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)

Whoops\Exception\ErrorException thrown with message "session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)" Stacktrace: #2 Whoops\Exception\ErrorException in /usr/local/vufind/vendor/laminas/laminas-session/src/SessionManager.php:242 #1 session_write_close in /usr/local/vufind/vendor/laminas/laminas-session/src/SessionManager.php:242 #0 Laminas\Session\SessionManager:writeClose in [internal]:0

Application frames (0) All frames (3)

2

Whoops\Exception\ErrorException

…/vendor/laminas/laminas-session/src/SessionManager.php242

1

session_write_close

…/vendor/laminas/laminas-session/src/SessionManager.php242

0

Laminas\Session\SessionManager writeClose

[internal]0

Open: /usr/local/vufind/vendor/laminas/laminas-session/src/SessionManager.php

     *
     * @return void
     */
    public function writeClose()
    {
        // The assumption is that we're using PHP's ext/session.
        // session_write_close() will actually overwrite $_SESSION with an
        // empty array on completion -- which leads to a mismatch between what
        // is in the storage object and $_SESSION. To get around this, we
        // temporarily reset $_SESSION to an array, and then re-link it to
        // the storage object.
        //
        // Additionally, while you _can_ write to $_SESSION following a
        // session_write_close() operation, no changes made to it will be
        // flushed to the session handler. As such, we now mark the storage
        // object isImmutable.
        $storage = $this->getStorage();
        if (! $storage->isImmutable()) {
            $_SESSION = $storage->toArray(true);
            session_write_close();
            $storage->fromArray($_SESSION);
            $storage->markImmutable();
        }
    }
 
    /**
     * Attempt to set the session name
     *
     * If the session has already been started, or if the name provided fails
     * validation, an exception will be raised.
     *
     * @param  string $name
     * @return SessionManager
     * @throws Exception\InvalidArgumentException
     */
    public function setName($name)
    {
        if ($this->sessionExists()) {
            throw new Exception\InvalidArgumentException(
                'Cannot set session name after a session has already started'

Arguments

              "session_write_close(): Failed to write session data using user defined save handler. (session.save_path: /var/lib/php/sessions)"

          

Open: /usr/local/vufind/vendor/laminas/laminas-session/src/SessionManager.php

     *
     * @return void
     */
    public function writeClose()
    {
        // The assumption is that we're using PHP's ext/session.
        // session_write_close() will actually overwrite $_SESSION with an
        // empty array on completion -- which leads to a mismatch between what
        // is in the storage object and $_SESSION. To get around this, we
        // temporarily reset $_SESSION to an array, and then re-link it to
        // the storage object.
        //
        // Additionally, while you _can_ write to $_SESSION following a
        // session_write_close() operation, no changes made to it will be
        // flushed to the session handler. As such, we now mark the storage
        // object isImmutable.
        $storage = $this->getStorage();
        if (! $storage->isImmutable()) {
            $_SESSION = $storage->toArray(true);
            session_write_close();
            $storage->fromArray($_SESSION);
            $storage->markImmutable();
        }
    }
 
    /**
     * Attempt to set the session name
     *
     * If the session has already been started, or if the name provided fails
     * validation, an exception will be raised.
     *
     * @param  string $name
     * @return SessionManager
     * @throws Exception\InvalidArgumentException
     */
    public function setName($name)
    {
        if ($this->sessionExists()) {
            throw new Exception\InvalidArgumentException(
                'Cannot set session name after a session has already started'

Open: [internal]

Environment & details:

GET Data

Key	Value
print	"1"

POST Data empty

Files empty

Cookies

Key	Value
language	"es"
VUFIND_SESSION	"9kipjs6j7vg6s33an28pvopni5"
ui	"standard"

Session

Key	Value
__Laminas	array:2 [`"_REQUEST_ACCESS_TIME" => 1749773744.6356 "_VALID" => array:1 [ "Laminas\Session\Validator\Id" => "9kipjs6j7vg6s33an28pvopni5" ]`]
SessionState	Laminas\Stdlib\ArrayObject {#906}
FlashMessenger	Laminas\Stdlib\ArrayObject {#1507}
SessionHelper	Laminas\Stdlib\ArrayObject {#1676}

Server/Request Data

Key	Value
REDIRECT_SCRIPT_URL	"/Record/dif.50951/TOC"
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REDIRECT_VUFIND_ENV	"development"
REDIRECT_VUFIND_LOCAL_DIR	"/usr/local/vufind/local"
REDIRECT_STATUS	"200"
SCRIPT_URL	"/Record/dif.50951/TOC"
SCRIPT_URI	"http://vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar/Record/dif.50951/TOC"
VUFIND_ENV	"development"
VUFIND_LOCAL_DIR	"/usr/local/vufind/local"
HTTP_ACCEPT	"/"
HTTP_USER_AGENT	"Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)"
HTTP_COOKIE	"language=es; VUFIND_SESSION=9kipjs6j7vg6s33an28pvopni5; ui=standard"
HTTP_ACCEPT_ENCODING	"gzip, br, zstd, deflate"
HTTP_HOST	"vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar"
HTTP_VIA	"1.1 squid-proxy-5b5d847c96-zgj6k (squid/6.10)"
HTTP_X_FORWARDED_FOR	"10.3.91.56"
HTTP_CACHE_CONTROL	"max-age=0"
HTTP_CONNECTION	"keep-alive"
PATH	"/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"
SERVER_SIGNATURE	"<address>Apache/2.4.52 (Ubuntu) Server at vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar Port 80</address>\n"
SERVER_SOFTWARE	"Apache/2.4.52 (Ubuntu)"
SERVER_NAME	"vufind10-pruebas.sigbunlp.bibliotecas.unlp.edu.ar"
SERVER_ADDR	"172.17.0.170"
SERVER_PORT	"80"
REMOTE_ADDR	"216.73.216.97"
DOCUMENT_ROOT	"/usr/local/vufind/public"
REQUEST_SCHEME	"http"
CONTEXT_PREFIX	""
CONTEXT_DOCUMENT_ROOT	"/usr/local/vufind/public"
SERVER_ADMIN	"webmaster@bibliotecas.unlp.edu.ar"
SCRIPT_FILENAME	"/usr/local/vufind/public/index.php"
REMOTE_PORT	"33950"
REDIRECT_URL	"/Record/dif.50951/TOC"
REDIRECT_QUERY_STRING	"print=1"
GATEWAY_INTERFACE	"CGI/1.1"
SERVER_PROTOCOL	"HTTP/1.1"
REQUEST_METHOD	"GET"
QUERY_STRING	"print=1"
REQUEST_URI	"/Record/dif.50951/TOC?print=1"
SCRIPT_NAME	"/index.php"
PHP_SELF	"/index.php"
REQUEST_TIME_FLOAT	1749773744.6251
REQUEST_TIME	1749773744

Environment Variables empty

Registered Handlers

0. Whoops\Handler\PrettyPageHandler

Introducción a la ciencia de la computación

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