dev assets

The "Digest"/dev/mem is a full image of physical memory that can be used to access physical memory, and the general usage is open ("/dev/mem", o_rdwr| O_sync), then mmap, then you can use the Mmap address to access the physical memory, which is actually a way to implement the user space driver. http://blog.csdn.net/wlp600/article/details/6893636# 1, user space-driven advantagesThere are severa

This article consists of two parts: 1. Process 2 of generating libmysql. A for DEV-C ++. Devc ++ in Windows C Language Access MySQL database environment configuration 1. The process of generating libmysql. A for DEV-C ++ aims: Because DEV-C ++ uses GCC, MySQL's libmysql. dll only supports visual stdio. Therefore, libmysql. A needs to be generated from libmysql.

When Linux runs the partprobe command, it encounters Unable to open/dev/sr0 read-write (Read-only file system), partprobesr0 When using fdisk to create a partition, we will use the partprobe command to allow the kernel to re-read the partition information to avoid restarting the system. However, the following error message "Warning: unable to open/dev/sr0 read-write (Read-only file system ). /

First, partition/dev/sdb:[Root@111cn.net/] # fdisk/dev/sdb # enter this deviceCommand (m for help): p # View partitions/Dev/sdb1 1 500 4016218 + 83 Linux/Dev/sdb2 501 1000 4016250 83 Linux/Dev/sdb3 1001 1305 2449912 + 5 ExtendCommand (m for help): d # delete a partitionParti

This article was reproduced from: http://blog.csdn.net/u013686019/article/details/50165059[HTML]View PlainCopy android:4.4.4 First, the problem analysisWhen the USB printer is plugged into an Android device, there is no printer node (/DEV/USB/LP0) generated in the System/dev directory.The first reaction is to check the printer device and access the Ubuntu-equipped PC, normal: /

During the FOTA differential upgrade, there was a retouch_binaries operation. I got stuck when I got here, and the waiting circle could not be completed in a few days. Later, I found that it was all done. Find a patch to solve the problem and change/dev/random to/dev/urandom. diff --git a/updater/install.c b/updater/install.cindex a1acdb9..2f2631a 100644--- a/updater/install.c+++ b/updater/install.c@@ -450,

WatchFirst introduce the Watch option, refer to here. The ability to update the Bundle.js file automatically after the related source file is changed.The watch function can be turned on by adding watch:true or performing webpack-w in the configuration file;The test found that all the JS, CSS and other modules related to (one or more) bundle.js changed, and the bundle.js files on the hard disk were automatically packaged and updated.Webpack-dev-serverW

The size of the Linux default (CentOS)/DEV/SHM partition is 50% of the system's physical memory, although the use of/DEV/SHM is much more efficient for file operations.However, it is seldom used in the current release software (except for Oracle mentioned earlier) and can be viewed through LS/DEV/SHM to see if there are any files below, and if not, the current sy

First let's get to know, what is Tmpfs and/dev/shm/? TMPFS is a memory-based file system on the Linux/unix system. TMPFS can use your memory or swap partitions to store files. This shows that TMPFS mainly stores the temporary files. It has the following 2 advantages: 1. The size of the dynamic file system. 2. Another major benefit of TMPFS is its lightning speed. Because a typical TMPFS file system resides completely in RAM, reading and writing can

1. Interpretation 1 >/ DEV/null 2> 1: redirect all standard output and error output to/dev/null, that is, discard all generated information. command> file 2> file and command> file 2> 1 are different. first, command> file 2> file means to send the standard output information and error output information generated by the command to file. Command> file 2> file: Both stdout and stderr are di

In Linux, ">/dev/null 2> 1" is often encountered in both crontab and Common commands ". For example, in a crontab job, if you do not want to send an email, you can use either of the following methods: First, set mailto = "" to null. [[emailprotected] etc]# cat crontabSHELL=/bin/bashPATH=/sbin:/bin:/usr/sbin:/usr/binMAILTO=""HOME=/# run-parts01 * * * * root run-parts /etc/cron.hourly02 4 * * * root run-parts /etc/cron.daily22 4 * * 0 root run-parts

Introduced/ dev/shm/ is a device that uses the Tmpfs file system, which is actually a special file system. the default size in Redhat is half of physical memory, so that time is not mkfs formatted. TMPFS is a memory-based virtual file system on the Linux/unix system .TMPFS can use your memory or swap partition to store the file ( that is, its storage space in virtual memory , the VM consists of real memory and swap ). Thus, TMPFS primarily stores s

Introduced / dev/shm/ tmpfs file system is actually a special file system. redhat use without mkfs formatted. Tmpfs is a memory-based Linux/unix system. Virtualfile System. TMPFS can use your memory or swap partition to store files (that is, its storage space isVirtual Memoryin, the VMbyReal Memoryand theSwapcomposition). Thus, TMPFS primarily stores staged files. It has the following 2 advantages: 1. The size of the dynamic file

Transferred from: http://loofeer.blog.51cto.com/707932/791065The default system will load/DEV/SHM, which is called TMPFS, some say with RAMDisk (virtual disk), but not the same. Like a virtual disk, TMPFS can use your RAM, but it can also be stored using your swap partition. And the traditional virtual disk is a block device, and requires a command such as MKFS to really use it, TMPFS is a file system, not a block device; you just install it and it's

error message:[Root@compute2 ~]# pvcreate-vvv/dev/sdb1 ... DEVICE/DEV/SDB1 not found (or ignored by filtering). No devices to process. Unlocking/run/lock/lvm/p_orphans _undo_flock/run/lock/lvm/p_orphans Lvmcache has no info for vgname "#orphans". Setting Global/notify_dbus to 1 completed:pvcreate-vvv/dev/sdb1 Solution idea:1. See if there are/

Linux empty device file and redirection Output/input redirection>>> File descriptor (file descriptor), which is represented by a number (usually 0-9.Common file descriptors are as follows:Default file descriptor name0 standard input stdin keyboard1. stdout screen output2. stderr screen output due to standard errors /Dev/null indicates an empty file device.1 indicates the system standard output. The default value is 1.>/

there is a device file FB * under/dev/. This is a special file of the character class.Code:Ls-L/dev/fb0 CrW-RW ---- 1 root video 29, 0 Jan 27 :32/dev/fb0If you do not have this file, you can also find other files such as/dev/Fb1,/dev/fb2.. If you cannot find these files, yo

In embedded arm development, when making the root file system with BusyBox, one of the directories that must be built is the/dev directory. This directory is important to all users because the directory contains all the external devices used in all Linux systems, that is, all the device nodes. When building the/dev directory, there are two approaches: static build and Mdev Device management tool building.

Today use BuildRoot to compile the file system to write to the Development Board boot prompt below the errorCan‘T open/dev/ttys0:no such file or directoryCan‘T open/dev/ttys0:no such file or directoryCan‘T open/dev/ttys0:no such file or directoryCan‘T open/dev/ttys0:no such file or directoryCan‘T open/

/Dev/null 2> 1 details today a friend suddenly saw the following content in his own Linux maintained:/var/spool/cron/root: www.2cto.com 30 19 ****/usr/bin/** dcon. sh>/dev/null 2> 159 23 ** 1-7/home/s **-log/squid-log.renew>/dev/null 2> 150 1 ** 1- 7/usr/local/src/** log. sh>/dev/null 2> 120 2 ** 1-7/home/sq **-log