DevGex Search

This technical paper provides an in-depth analysis of PS command output truncation issues in Linux environments, exploring multiple effective solutions. The focus is on parameter configuration for less and most pagers, detailed explanation of -w and -ww options' mechanisms, and code examples demonstrating complete process command line display. The paper also discusses behavioral differences in piped output and compatibility considerations across Unix variants.

This article provides a comprehensive analysis of the missing ps command issue in Debian-based Docker containers. By examining Docker's minimalist image design principles, it explains the absence of the procps package and offers two practical solutions: temporary installation in running containers and permanent integration in Dockerfile. The paper also discusses the importance of ps command in container debugging and best practices for process monitoring in Docker environments.

This technical paper provides an in-depth exploration of Docker container listing commands, covering detailed parameter analysis of core commands like docker ps and docker container ls, including running state filtering, output format customization, container screening, and other advanced features. Through systematic command classification and practical code examples, it helps readers comprehensively master core skills in Docker container management and improve container operation efficiency.

This paper provides an in-depth exploration of various technical methods for retrieving command line arguments of running processes in Unix/Linux systems. By analyzing the implementation mechanisms of the /proc filesystem and different usage patterns of the ps command, it详细介绍Linux environment-specific approaches through /proc/<pid>/cmdline files and ps command implementations, while comparing differences across Unix variants (such as AIX, HP-UX, SunOS). The article includes comprehensive code examples and performance analysis to help system administrators and developers choose the most suitable monitoring solutions.

This article systematically introduces multiple methods for examining running processes in the macOS terminal. It begins with a detailed analysis of the top command's real-time monitoring capabilities, including its interactive interface, process sorting, and resource usage statistics. The discussion then moves to various parameter combinations of the ps command, such as ps -e and ps -ef, for obtaining static process snapshots. Finally, the installation and usage of the third-party tool htop are covered, including its tree view and enhanced visualization features. Through comparative analysis of these tools' characteristics and applicable scenarios, the article helps users select the most appropriate process examination solution based on their needs.

This article delves into the common reasons why the docker ps command displays an empty list in Docker, focusing on the core distinction between images and containers. Through analysis of a user case, it explains how to correctly use docker images to view images, docker run to start containers, and docker ps to see running or stopped containers. Additionally, it covers troubleshooting methods like restarting the Docker service, helping readers fully grasp Docker workflows and resolve similar issues.

This paper thoroughly examines the common issues of word splitting and filename expansion when looping through command output in Bash scripts. Through analysis of a typical ps command output processing case, it reveals the limitations of using for loops for multi-line output. The article systematically explains the mechanism of the Internal Field Separator (IFS) and its inadequacies in line processing, while detailing the superiority of the while read combination. By comparing the practical effects of for loops versus while read, along with alternative approaches using the pgrep command, it provides multiple robust line processing patterns. Finally, for complex fields containing spaces, it offers practical techniques for field order adjustment to ensure script reliability and maintainability.

This article provides an in-depth exploration of various methods to retrieve start times for long-running processes in Linux systems. By analyzing the lstart, etime, and etimes formatting options of the ps command, it explains in detail how to accurately obtain process start timestamps and runtime durations. The article compares the advantages and disadvantages of different approaches, including technical details of directly reading process information through the /proc filesystem, and offers practical command-line examples and script implementations. For various usage scenarios, corresponding best practice recommendations are provided to help system administrators and developers accurately monitor and manage long-running processes.

This article provides a comprehensive exploration of methods for effectively monitoring and managing background processes initiated via the nohup command in Linux systems. It begins by analyzing the working principles of nohup and its relationship with terminal sessions, then focuses on practical techniques for identifying nohup processes using the ps command, including detailed explanations of TTY and STAT columns. Through specific code examples and command-line demonstrations, readers learn how to accurately track nohup processes even after disconnecting SSH sessions. The article also contrasts the limitations of the jobs command and briefly discusses screen as an alternative solution, offering system administrators and developers a complete process management toolkit.

This paper provides an in-depth examination of column-based splitting techniques for command output processing in Bash environments. Addressing the challenge of field extraction from aligned outputs like ps command, it details the tr and cut combination solution through squeeze operations to handle repeated separators. The article compares alternative approaches like awk and demonstrates universal strategies for variable format outputs with practical case studies, offering valuable guidance for command-line data processing.

This article explores methods to detect if an Android application is running using ADB commands, with a focus on package name-based detection. It details the core techniques of using the 'ps' command for Android versions below 7.0 and the 'pidof' command for Android 7.0 and above, supplemented by alternative approaches such as filtering with grep and awk, and retrieving the current foreground application. The content covers command principles, code examples, and best practices for automation and system monitoring scenarios.

This article comprehensively explores various methods for monitoring CPU and memory usage of specific processes in Linux systems. It focuses on practical techniques using the ps command, including how to retrieve process CPU utilization, memory consumption, and command-line information. The article also covers the application of top command for real-time monitoring and demonstrates how to combine it with watch command for periodic data collection and CSV output. Through practical code examples and in-depth technical analysis, it provides complete process monitoring solutions for system administrators and developers.

This paper provides an in-depth technical analysis of one-line commands for automatically finding and terminating processes in Bash environments. Through detailed examination of ps, grep, and awk command combinations, it explains process ID extraction, regex filtering techniques, and command substitution mechanisms. The article compares traditional methods with pgrep/pkill tools and offers comprehensive examples for practical application scenarios.

This paper provides an in-depth examination of different methods for executing command-line calls in Python, focusing on the limitations of the os.system function that returns only exit status codes rather than command output. Through comparative analysis of alternatives such as subprocess.Popen and subprocess.check_output, it explains how to properly capture command output. The article presents complete workflows from process management to output handling with concrete code examples, and discusses key issues including cross-platform compatibility and error handling.

This technical article provides an in-depth exploration of methods for executing single SQL commands directly from the command line in Oracle SQL*Plus, eliminating the need for temporary script files. Through detailed analysis of piping techniques, input redirection, and immediate command execution, the article explains implementation principles, use cases, and considerations for each approach. Special attention is given to differences between Windows and Unix/Linux environments, with complete code examples and best practice recommendations.

This paper comprehensively examines technical solutions for passing passwords to su, sudo, and ssh commands in Linux environments, focusing on the -S option of sudo command for standard input password verification. It details various automation authentication technologies including sshpass tool, expect scripts, and SSH key authentication. Through comparative analysis of different methods' advantages and disadvantages, it provides secure and reliable password passing solutions suitable for automation scripts and system administration scenarios.

This article details how to monitor heap memory usage of a running JVM from the command line, specifically for scripting needs in environments without a graphical interface. Using the core tool jstat, combined with Java memory management principles, it provides practical examples and scripting methods to help developers effectively manage memory performance in application servers like Jetty. Based on Q&A data, with jstat as the primary tool and supplemented by other command techniques, the content ensures comprehensiveness and ease of implementation.

This technical paper comprehensively examines three primary methods for obtaining Process ID (PID) from process names in Mac OS X: using ps command with grep and awk for text processing, leveraging the built-in pgrep command, and installing pidof via Homebrew. The article delves into the implementation principles, advantages, limitations, and use cases of each approach, with special attention to handling multiple processes with identical names. Complete Bash script examples are provided, along with performance comparisons and compatibility considerations to assist developers in selecting the optimal solution for their specific requirements.

This article provides a comprehensive guide on correctly executing PostgreSQL psql commands within Docker environments. By analyzing common 'psql command not found' errors, it delves into the parameters and usage scenarios of docker exec command, offering complete code examples and environment configuration instructions. The content covers key concepts including container connectivity, user authentication, and database selection, helping Docker beginners quickly master PostgreSQL container operations.

This article provides an in-depth exploration of various methods for stopping Android applications from the command line using Android Debug Bridge (ADB), with detailed analysis of the technical principles and application scenarios for adb shell am force-stop and adb shell pm clear commands. The paper comprehensively examines the fundamental architecture and operational mechanisms of ADB tools, compares the advantages and disadvantages of different stopping methods, and presents complete test process optimization solutions. Through practical code examples and thorough technical analysis, it helps developers understand how to leverage ADB tools for rapid application termination and state reset, significantly improving testing efficiency.