Tag: printf

[c++] In-depth analysis of your favorite stringstream and snprintf performance

I recently wrote two similar modules in a program. One uses snprintf to output intermediate data, and the other uses stringstream lazily. And guess what? The frame is actually pressed! ! Who is holding back performance? Performance analysis experiment from Alibaba Cloud I searched online and found that someone had done a performance analysis experiment. […]

Serial communication (3) Implementation of printf serial port output redirection and sending of one frame and one string of data

This article is the original csdn first release of the blogger. I hope it will be helpful to you after reading it. Please correct me if I have any shortcomings! Let’s communicate and learn together and make progress together! >Personal homepage: @日月同光, a blog that coexists with me >You are welcome to like the original […]

CLion wildfire STM32 project printf problem

After reading some articles, I added syscalls.c to the project and placed it in the user folder. The syscall.c file comes from the Core folder of the project directory I created with STM32CubeMX: Copy to the User folder, refresh CMake, and Debug again: Tips: undefined reference to `_sbrk’ This syscalls.c only lacks this function definition, […]

printf function and scanf function

printf function and scanf function 1. printf function 1.1 Function and usage 1.2 Placeholders 1.3 Output format 2. scanf function 2.1 Basic usage 2.2 Return value of scanf 2.3 Placeholders 1. printf function 1.1 Function and usage The printf function can output parameter text to the screen, and the header file is stdio.h #include<stdio.h> int […]

Do you really know how to printf/scanf?

Directory printf basic output Borrow placeholder output Use placeholders to limit output formats Limit output width Always show plus and minus signs Limit decimal places Output part of the string printf examples and results scanf basic skills Principles and examples Note on usage return value printf The original intention of printf is to format the […]

Regarding the problem of printf in fork multi-process

About the problem of printf in fork multi-process Program 1 int main(int argc, char **argv) {<!– –> int remaining = 4; int child_pid; while (remaining > 0) {<!– –> child_pid = fork(); if (child_pid == 0) break; remaining–; } printf(“P”); return 0; } The above program will output: PPPPP (5 P) Program execution process: remain=4， […]

[C language] printf()

Table of Contents Interpretation of its header files Basic usage Placeholder Type of placeholder (alphabetical order) printf output width printf can limit the minimum width of placeholders: Floating point type, decimal point also occupies a width printf output always retains signs Printf output floating point number limits the number of decimal places Floating point output […]

Understanding the printf function 1

Look at the following code: #include <stdio.h> int main(int argc, const char *argv[]) { printf(“%s\ “,”peng”,”dopmg”,”Shijiazhuang Railway University”); return 0; } Change the code to: #include <stdio.h> int main(int argc, const char *argv[]) { printf(“%s%s%s\ “,”peng”,”dopmg”,”Shijiazhuang Railway University”); return 0; } The result becomes: Formatted output: 1 #include <stdio.h> 2 #include <limits.h> 3 4 int […]