SANTIAGO, CHILE -- Every night at 10, Jose Cardenas, a Chilean magazine editor, goes to an old prison in the center of Santiago, where he is searched and locked in a cell to sleep.

Every morning at 6, the soft-spoken 37-year-old journalist is allowed to return to the offices of Analisis, a polemical left-of-center weekly produced in the musty quarters of a small suburban house.

Cardenas has shuttled daily between cell and office for about five months. He has another 13 months to go before completing a sentence handed down by the Supreme Court, which found him guilty of defaming Chile's president, Gen. Augusto Pinochet, in several editorials.

His situation illustrates the shaded, hedged spaces for expression that exist precariously under Chile's military dictatorship. No law blocks Cardenas from publishing articles accusing the government of terrorism, torture and intolerance. But his nights in jail indicate how limited his maneuvering room is.

That his magazine and other anti-Pinochet publications circulate openly is cited by Chilean authorities as proof that free expression is permitted. Indeed, kiosks offer a wide selection not only of Chilean papers and magazines but also uncensored foreign ones.

Books accusing the 14-year-old military government of abuses are displayed in store windows alongside the works of Pinochet. Plays portraying the government's repression are staged in crowded theaters.

Most opposition parties, banned after the 1973 coup, have been permitted to register anew. The government did not interfere with an opposition rally Nov. 19 in Santiago's main park attended by an estimated 100,000 to 150,000 people.

But such allowances for independent voices are kept within strict bounds. And those who speak out are often subject not just to reprisals by legal authorities but death threats as well.

According to the National Press Association, there are 34 laws and "transitory" constitutional articles restraining press freedom in the name of national security, military justice and the battle against terrorism. The government applies them selectively. The opposition press tests the limits while practicing a certain measure of self-censorship.

At the time of the 1973 coup that overthrew the elected leftist government of Salvador Allende, the military closed many publications and radio stations. Gradually, the opposition has won back a voice, particularly since 1983, which marked the outbreak of anti-Pinochet protests. Four main opposition magazines and two dailies critical of the government now circulate in Santiago. Two national radio networks regularly report on human rights abuses and opposition activities.

Pinochet's critics attribute the loosening of press restrictions to domestic and foreign political pressures. But some suspect that Pinochet has willingly lifted the lid as a vent for social unrest and an effort to establish his own legitimacy. He may also have figured, correctly, that Chile's fractured opposition groups would use the restored space to quarrel among themselves.

The government still limits expression in many ways. It retains the power to authorize establishment of new media. It frequently jails reporters, usually on charges of offending Pinochet or the honor of the armed forces. It has stripped the Communist Party and two smaller Marxist groups of constitutional rights. And in a move that has upset the opposition, it issued a law in October threatening heavy fines for and suspension of media that report on the banned parties.

While the government does permit opposition views to appear in print and on the radio, it has not let opposition politicians appear on television. The official reason is to preserve television's nonpolitical character. One channel is owned by the state; the other two national stations are managed by military-controlled universities.

The government often employs economic power rather than legal measures to try to keep news organizations in line. Editors of two new opposition dailies, La Epoca and Fortin Diario, said Chilean companies have come under pressure from Pinochet's supporters not to place ads in the publications.

Meanwhile, Santiago's two major papers, El Mercurio and La Tercera, owe large sums to the state-managed Banco del Estado. Although the papers have been printing more opposition news since the recent launching of the new competing dailies, their editors still consult closely with government information officials over what items and photographs to publish.

"There is not press freedom in Chile, despite the existence of independent media that criticize the government's management and are its tenacious adversaries," said Emilio Filippi, the editor of La Epoca, in a report to the Inter-American Press Association, which held its annual meeting here in mid-November.

More than 20 journalists currently face prosecution. One case involves Monica Gonzalez, a reporter for Analisis, who was jailed for two weeks and is being sued in civil court for reporting an unflattering description of Pinochet given by Christian Democratic leader Andres Zaldivar in an interview.

Zaldivar called the Chilean president "coarse, of low intellectual level, brutishly audacious." He also said the general had developed a "dependency" on power similar to that of an addict on drugs. Instead of prosecuting Zaldivar, the Interior Ministry has gone after Gonzalez.

Pinochet contends that press restrictions are necessary to protect the rights of all Chileans and to guard the country from what he says is an intense, skillful international Marxist campaign to distort the truth.

"Solid legal and constitutional barriers have been created here to prevent totalitarian parties and groups from using the press as an instrument of their proselytizing," Pinochet said in a keynote address to the press association.

The Chilean leader described his country as victimized not only by a communist disinformation campaign but by a foreign press that he said does not understand the Chilean reality.

"No government has suffered the incomprehension of the foreign press as Chile has," he said.

In Valparaiso this month, several political and human rights activists who had expressed solidarity with other threatened persons awoke one morning to find on their own doorsteps cats whose throats had been cut.