"Once when I opened the door of a vendor's vehicle to talk to him, another man sitting inside suddenly took out a long knife and waved it violently in front of me. I was stunned at that moment. Luckily I evaded it and the knife fell beside the seat," Song said.

Browsing online, Song has found that posts cursing chengguan are exceptionally popular.

"Having worked as a chengguan for three years and experienced various hardships during work, I felt the urge to share my experiences so that more people will understand us," he said.

Song said the greatest difficulty in work is misunderstanding from the public.

"When a dispute happens between vendors and us, we are always blamed by the passers-by," Song said. "Some vendors take advantage of the public mind to escape punishment. It really makes us angry but helpless."

The stress of the job nearly brought a quick end to his career, as Song submitted a resignation letter half a year after becoming a chengguan.

It was not approved.

"Now I'm used to it. When I'm a little depressed, I go play basketball, play pool, or go to a KTV to sing with my friends," he said.

He hopes the book will change people's opinions of chengguan. "But I don't expect it to reverse our image immediately. It takes time."

The book is "real and interesting. The language is humorous and it reveals a true and poignant side of a chengguan's life and work," said Wang Dan, sales manager with Beijing Institute of Technology Press, who contacted Song and published the book.

Although a little immature and cynical in the eyes of his instructor, He Xiao, Song is "a man with ideas, helpful and serious", said Mao Fei, one of Song's high school classmates.

"I feel it absurd when some officials swear that we should eliminate all vendors from the city," Song said. "How is it possible when there is such a big demand for roadside stands?"

Song said he believes there should be room for vendors to survive.

"We need vendors. Their low-price products meet people's needs," he said.

"But to deal with this problem requires more efforts besides chengguan. The communities, for example, can take action to help these vendors to do business in an orderly manner, so that both the vendors and the residents nearby can be happy," he said.