While the Iranian government has taken a nonchalant view toward the imposition of full-scale U.S. economic sanctions, a growing anxiety among the Iranian people is reflected daily here in the growing lines in front of supermarkets and butcher shops.

The rush to stock up on basic items, already in short supply, is clear evidence that the boycott, while perhaps not being enought to bring the revolutionary government to its knees, is causing real concern among Iranians.

Under a combined impact of revolutionary turmoil and disruption of traditional trade links, Iran's economy already is bogged down in the mire of its post-revolutionary chos that has produced shortages, skyrocketing prices and a thriving smuggling business from other Persian Gulf countries.

The Iranian government is talking a brave game, but it also displayed signs of concern when it asked ministries and government organizations this week to economize in the use of computers and to "introduce manual systems" instead. t

"Until last week we were receiving parts and certain materials from the Paris office of IBM," an Iranian manager complained. "Now everything is stopped and we can't get computer spares from anywhere else."

Much of Iran's oil pipeline network, distribution of electricity and banking system is run with the aid of U.S.-supplied computers, many of them made by IBM.

There were no indications thus far that the U.S. sanctions would force the release of the 50 American hostages. Nor is it clear, given a drift toward closer trade relations with Eastern Europe, that wider trade sanctions by European allies or Washington's blockade of Iranian ports would cripple the economy.

But the prospect of such actions is clearly worrying Iranian economic planners since even the limited U.S. trade embargo currently in effect is beginning to take its toll.

Even without the sanctions, the situation has been steadily deteriorating following an exodus of experienced personnel, outlandish labor demands, onerous restrictions on foreign transactions, a burgeoning if lackadaisical government bueaucracy and a series of nationalizations and expropriations.

The economy, according to analysts here, is at a virtual standstill despite massive oil revenue now running at a rate of $23 billion annually.

"People don't work in the country, they just use the oil money," an Iranian said.

The already low productivity, he added, has been exacerbated by the "infiltration" of workers' councils in various enterprises by leftists seeking to "sabotage the production process."

Many officials in President Abol Hassan Bani-Sadr's government had hoped that the sanctions would serve to rally Iranians to greater productivity. So far, however, the ruling Revolutionary Council feels obliged to issue ever harsher warnings that workers who stage strikes or slowdowns will be branded counter-revolutionaries and face Islamic justice.

Another sign of concern about sanctions was the government's announcement this week of a "war economy plan." Revolutionary Council member Ezzatollah Sahabi said Iran in the future would acquire raw materials from "friendly countires" such as Libya, Algeria, India and Pakistan.

Iran's dependence on imports is spread throughout the economy, from feed grains to unassembled automobile kits. In one example of how the lack of an imported product can have a wider effect, the managing director of the Iran Mild Industries explained in a radio interview that a current shortage of milk was due to a lack of cardboard containers imported entirely from abroad.

While arguing that in the long run the U.S. sanctions favor Iran because they help promote a "self-reliant economy," Islamic economist Hossein Baher conceded in a local newspaper interview that "it is possible that we will be a bit hard-pressed in terms of consumption of goods and spare parts."

Iran's Minister of Commerce is known to have privately expressed worry about the economic effects of a closure by the United States of Iran's Persian Gulf port.

"If the Persian Gulf is closed, we will really have a lot of problems," said an Iranian politician. He added that he did not think Washington would take such an action, because it would push Iran into the embrace of its neighbor to the north, the Soviet Union.

Iran cold import goods over land only from Turkey and Pakistan. Iran is not on good terms with the other two neighbors, Iraq and Afghanistan.

"It's not finished when you mine the ports," a European diplomat cautioned, however. "It's only the beginning." He said a military blockade of Iran would risk degenerating into a wider conflict, possibly involving the Soviet Union. r

Short of a blockade, some diplomats feel that Iran may be insulated from the effects of sanctions because of an already rampant smuggling trade in the Persian Gulf.

During a trip to southern Iran, a month ago, one European diplomat saw long lines of trucks being loaded with tons of smuggled goods, including American wheat originally shipped to Kuwait. He said that the Iranian demand for smuggled goods has caused a four-fold increase in Western exports to the Gulf sheikdom of Dubai in the last six months, and that both customs officials and Revolutionary Guards turn a blind eye to the illicit trade at the Iranian port of Bandar Abbas and Chah Bahar.

"This is why I don't believe in the effectiveness of the sanctions," the diplomat said. "I can understand the Americans' view that up to now Iran has not paid the price of the hostage crisis. But sanctions will be difficult to enforce."

Another factor that could blunt sanctions is a marked improvement in Iran's agricultural outlook. Good weather this year and exhortations by Ayatollah Ruhollah Khomeini to work the land as a religious duty have combined for a relatively good wheat harvest, somewhat reducing Iran's dependence on imports.

Further softening the potential affects of sanctions has been Iranian efforts to diversify the sources of its imports, particularly of food. As a result, Iran now is purchasing more foodstuffs and agricultural equipment from East bloc countries such as Romania, Bulgaria, East Germany and Czechoslovakia, and has become one of the world's top importers of meat from Australia and New Zealand. Australia also supplies much of Iranian grain imports.

While those two countries have profited substantially from increased Iranian trade, exports to Iran by the United States, Japan and all European Common Market countries fell off sharply in 1979 from the previous year.

Even before the embassy seizure, U.S. sales to Iran had dropped from $3.7 billion in the first nine months of 1978 to a little more than $1 billion in the same period of 1979. Afterward they trickled to only a few million dollars a month.

"The main thing that Iranians have to worry about is getting spare parts," an economist said. "This is particularly acute in the military and the oil industry."

While Iran could eventually get needed U.S.-made oil industry equipment indirectly from third countries, the problem is more complex for spares to keep Iran's largely American-supplied armed forces ready for battle.

Since the American hostages were seized Nov. 4, diplomats here said, Western countries have joined the United States in halting all military deliveries to Iran.