The French people are closing ranks and throwing their support behind the government's efforts to boost security in the wake of the country's worst terrorist attacks, a survey shows.

Fully 84 per cent of the population, known as fierce defenders of civil liberties, say they are willing to accept more restrictive measures if they would lead to better security, according to a survey of 910 people commissioned by Le Figaro newspaper and RTL radio.

The survey was published on Tuesday as French President Francois Hollande moved to extend by three months a state of emergency declared last Friday, after nine terrorists killed 129 people and wounded hundreds in coordinated attacks in Paris.

Mr Hollande, who has said France is at war with the Islamic State in Iraq and Syria (ISIS) militant group which claimed responsibility for the attacks, also wants the Constitution to be amended to grant more powers to the police. The state of emergency gives the authorities the power to search homes without a warrant, impose curfews, restrict traffic, ban public gatherings and impose controls on the media.

And most French appear prepared to accept such draconian measures, according to the Le Figaro survey, which was conducted via an online questionnaire on Monday.

About 84 per cent of respondents said they were prepared to accept more controls and "a certain limitation of your liberties". Of these, half said that they were "very prepared" while the other half were "quite prepared".

Only 16 per cent said they were not ready for such restrictions.

"From now on, not only do the French support the rhetoric of war, they also support decisions which lead to a restriction of public liberties," said Mr Jerome Fourquet, a director of Ifop, the survey company.

Meanwhile, many French are showing their defiance in a different way: venturing back to cafes and bars.

"This was an attack on our way of life," said Mr Maxence Lezeau, sitting at a tiny bistro table at Le Barometre in the Boulevard Voltaire, scene of some of the carnage.

"With this simple act, we're showing that we are never going to let the terrorists get at the heart of France," he told The New York Times.

French Muslims are included in the sense of unity. Many, including Islamic veil-wearing student Sabah Zouaghi, told Le Monde newspaper they have not felt more hostility in the wake of the attacks, unlike in the aftermath of the January attacks on satirical magazine Charlie Hebdo and a Jewish supermarket.

Ms Farah Maiza, vice-president of the inter-religion association Coesister, told the paper: "This time, it was the French people, whatever their convictions may be, who were targeted, and not an (anti-Islam) symbol like Charlie Hebdo."