xrandr_LINUX技术专题之FEDORA专家命令

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fedora命令大全

fedora命令大全一、安装和登陆命令1、startx进入图形界面2、init 5进入图形界面3、init 3进入字符界面4、login登陆5、poweroff关机-p 关闭机器的时候关闭电源-n 在关闭机器时不同步数据-w 不做关机的操作，只是把这个操作记录到日志里-d 不把关机的信息记录到日志文件里-f 不调用shutdown6、shutdown关机重启命令格式：shutdown [选项] 时间[信息]时间是必要参数，一定要加，可以用now，也可以用+5信息在关机的时候给用户的信息-t 这个参数后面需要加数字，比如5，表示在发出关机信号5秒后开始关机-k 不做真正的关机，只是通知一下所有的用户。

-r 重启计算机-h 关机后关闭电源-f 在重新启动的时候跳过fsck（磁盘检查程序）-F 重启时，忽略fsck程序（同-f一样）-c 取消已在执行的关机动作例：#shutdown -k now just kid#shutdown -h now system shut down now7、halt关机，选项同poweroff一样8、reboot重启计算机9、mount挂载文件系统umount卸载文件系统挂载光盘#mount -t iso9660 /dev/cdrom /mnt/cdrom 或者#mount /mnt/cdrom 卸载光盘#umount /mnt/cdrom退出光盘#eject送入光盘#eject -t挂载软盘#mount /mnt/floppy卸载软盘#umount /mnt/floppy挂载本地FAT32分区，并使挂载后显示中文#mount -t vfat -o iocharset=cp936 /dev/hda1 /mnt/win卸载#/umount /mnt/win挂载U盘或者移动硬盘#mount -o iocharset=utf8 /dev/sda1 /mnt/usb卸载 #umount /mnt/usb如果本地语言环境不是utf8，而是gb18030，需使用下面的命令挂载#mount -o iocharset=gb2312 /dev/sda1 /mnt/usb 挂载一个光盘镜像至本地/mnt/cdrom目录，用下面的命令#mount -t iso9660 -o loop /tmp/cd.iso /mnt/cdrom10、linux text字符界面下安装操作系统的命令11、linux askmethod 选择不同方法安装操作系统的命令二、图形化界面相关命令1、setup系统设置2、ntsysv服务启动设置3、gdmsetup / gdmconfig 登陆设置4、networkconfig / thizconfig 网络设置5、gnome-volume-control音量控制6、kcontrol KDE控制中心7、kpersonalizer KDE设置向导8、xmtr 网络检测命令三、信息显示命令1、time显示特定指令执行时所需消耗的时间及系统资源等资讯2、data 显示或设定系统的日期与时间若是不以加号作为开头，则表示要设定时间，而时间格式为MMDDhhmm[[CC]YY][.ss]，其中MM 为月份，DD 为日，hh 为小时，mm 为分钟，CC 为年份前两位数字，YY 为年份后两位数字，ss 为秒数#date 0811********.35 3、cal 显示日历#cal –m #cal –s #cal 2006 #cal 08 20064、uptime提供使用者下面的资讯，不需其他参数：现在的时间系统开机运转到现在经过的时间连线的使用者数量最近一分钟、五分钟和十五分钟的系统负载参数：-V 显示版本资讯5、last 显示系统开机以来或是从每月初登入者的讯息6、dmesg显示系统启动的信息7、uname 显示系统信息-m 显示硬件型号-n 显示主机名-r 显示内核版本-S 显示操作系统类型-V 显示操作系统的版本-a 显示全部信息8、id 显示真实和有效的UID和GID9、hostname 显示或设置系统的主机名-a 显示主机的别名-d 显示DNS域名-F 从指定文件中读取主机名-i 显示主机的IP地址10、who或w 显示在线登陆用户-q 显示全部的登陆名和登陆数#w 显示系统中当前用户的信息#w user username 仅显示指定用户的信息11、whoami显示用户自己的身份12、whois 查询域名注册及IP地址相关信息#whois /doc/4e3608708.html,小技巧：如果想注册一个域名，可以用whois工具查询一下是否有人注册。

Fedora Linux 系统调用或常用命令详细解析 roqet

NAMEroqet − Rasqal RDF query utilitySYNOPSISroqet[OPTIONS]<query-URI> [base-URI]roqet[OPTIONS]-e query-string [base-URI]DESCRIPTIONThe roqet utility allows querying of RDF content using the Rasqal RDF query library,printing the results in variable bindings, RDF graph or boolean format.The query is read from query-URI and the optional base-URI is used as the base URI of the query if present.MAIN OPTIONSroqet uses the usual GNU command line syntax, with long options starting with two dashes (‘-’) if sup-ported by the getopt_long function.Otherwise only the short options are available.−e, −−exec QUERYExecute the query in the argument QUERY instead of reading the query from a URI (when -e isnot given).−i, −−input LANGUAGESet the input query LANGUAGE to one of’sparql’ (SPARQL Query Language for RDF,default) or’rdql’ (RDF Data Query Language).The list of supported languages is given in the help summarygiven by−h.−r,−−results FORMATSet the query results format.For variable bindings, the values of FORMAT vary upon what Rasqal supports but include ’sim-ple’ for a simple text format (default), ’xml’ for the SPARQL Query Results XML format and’json’ for a JSON version of the results.For RDF graph results, the values of FORMAT are ’ntriples’ (N-Triples, default), ’rdfxml-abbrev’(RDF/XML Abbreviated), ’rdfxml’ (RDF/XML), ’turtle’ (Turtle), ’json’ (RDF/JSON resourcecentric), ’json-triples’ (RDF/JSON triples) or ’rss-1.0’ (RSS 1.0, also an RDF/XML syntax).The exact list of formats depends on what libraptor(3) was built with but is given correct in theusage message with −h.OTHER OPTIONS−c, −−countOnly count the triples and produce no other output.−D, −−data URIAdd RDF data source URI (not a named graph).If no data sources are given, the query itself mustpoint to the data such as via SPARQL or RDQL FROM uri statements.−d, −−dump−query FORMATPrint the parsed query out in a given FORMAT one of ’debug’, ’structure’ or ’sparql’−f,−−feature NAME(=V ALUE)Set query feature NAME to the VALUE or integer 1 if omitted.The known features can be shownwith-f help or--feature help.−G, −−named URIAdd RDF data source URI (named graph)−h, −−helpShow a summary of the options.−n, −−dryrunPrepare the query but do not execute it.−q, −−quietNo extra information messages.−s, −−source URIAdd RDF data source URI (named graph)URI by adding it to the list of query data source URIs.FORMAT to ’simple’ (default) or ’xml’ (an experimental XML format)−v,−−versionPrint the rasqal library version and exit.−w,−−walk-queryWalk the query and display it using the API.EXAMPLESroqet sparql-query-ﬁle.rqRun a SPARQL query contained in the local ﬁle sparql-query-ﬁle.rq.The data used would be described in FROM statements in the query ﬁle.roqet -q -i sparql /sparql-query.rqRun a SPARQL query that is in the web at URI /sparql-query.rq without an extra mes-sages (quiet, -q).roqet -q -i rdql rdql-query-ﬁle.rdql /base/Run an RDQL query from a local ﬁle rdql-query-ﬁle.rdql but using base URI /base/ to resolve any relative URIs.roqet -q -i sparql -r xml /sparql-query.rqRun a SPARQL query that is in the web at URI /sparql-query.rq and format the results in the SPARQL Query Results XML format with no extra messages.roqet -i sparql -e ’SELECT * WHERE { ?s ?p ?o }’ -D stuff.rdfRun a SPARQL query given on the command line against data in the ﬁle stuff.rdf. The type of the ﬁle will be guessed and likely is of format RDF/XML.CONFORMING TOSPARQL Query Language for RDF,Eric Prud’hommeaux and Andy Seaborne (eds), W3C Recommenda-tion, 15 January 2008./TR/2008/REC-rdf-sparql-query-20080115/SPARQL Query Results XML Format,Jeen Broekstra and Dave Beckett (eds), W3C Recommendation, 15 January 2008./TR/2008/REC-rdf-sparql-XMLres-20080115/RDQL - A Query Language for RDF,Andy Seaborne, W3C Member Submission 9 January 2004 /Submission/2004/SUBM-RDQL-20040109/SEE ALSOlibrasqal(3),rasqal-conﬁg(1),libraptor(3)CHANGESAUTHORDave Beckett - /。

fedora使用技巧

fedora使用技巧Fedora使用技巧Fedora是一款流行的Linux发行版，它基于Red Hat Enterprise Linux（RHEL）开发而来，提供了一个稳定、安全且功能丰富的操作系统。

本文将为您介绍一些Fedora使用技巧，帮助您更好地利用这个操作系统。

一、使用终端终端是Fedora中非常强大的工具，通过命令行可以完成许多任务。

以下是一些常用的终端命令：1.安装软件包：使用dnf命令可以方便地安装软件包，例如：dnf install package_name。

2.更新系统：使用dnf命令可以更新系统，例如：dnf update。

3.查找文件：使用find命令可以快速查找文件，例如：find / -name file_name。

4.压缩和解压缩文件：使用tar命令可以进行文件的压缩和解压缩，例如：tar -cvf archive.tar file_name。

二、使用软件包管理器Fedora使用dnf作为默认的软件包管理器，它可以方便地管理系统软件包。

以下是一些相关的技巧：1.添加软件源：可以使用dnf命令添加第三方软件源，例如：dnf config-manager --add-repo repo_url。

2.搜索软件包：可以使用dnf命令搜索软件包，例如：dnf search package_name。

3.卸载软件包：可以使用dnf命令卸载软件包，例如：dnf remove package_name。

4.清理系统：可以使用dnf命令清理系统缓存，例如：dnf clean all。

三、使用GNOME桌面环境Fedora默认使用GNOME桌面环境，以下是一些相关的技巧：1.自定义桌面：可以通过系统设置来自定义桌面的外观和行为，例如：更改壁纸、调整面板位置等。

2.使用扩展：可以通过GNOME扩展来增强桌面功能，例如：添加天气插件、任务栏等。

3.使用快捷键：可以通过快捷键来提高工作效率，例如：Ctrl+Alt+T打开终端、Super键打开应用程序菜单等。

xrdb_LINUX技术专题之FEDORA专家命令

NAMExrdb - X server resource database utilitySYNOPSISxrdb[-option ...] [ﬁlename]DESCRIPTIONXrdb is used to get or set the contents of the RESOURCE_MANAGER property on the root window of screen 0, or the SCREEN_RESOURCES property on the root window of any or all screens, or everything combined. You would normally run this program from your X startup ﬁle.Most X clients use the RESOURCE_MANAGER and SCREEN_RESOURCES properties to get user pref-erences about color,fonts, and so on for applications.Having this information in the server (where it is available to all clients) instead of on disk, solves the problem in previous versions of X that required you to maintain defaultsﬁles on every machine that you might use.It also allows for dynamic changing of defaults without editing ﬁles.The RESOURCE_MANAGER property is used for resources that apply to all screens of the display.The SCREEN_RESOURCES property on each screen speciﬁes additional (or overriding) resources to be used for that screen.(When there is only one screen, SCREEN_RESOURCES is normally not used, all resources are just placed in the RESOURCE_MANAGER property.)The ﬁle speciﬁed byﬁlename(or the contents from standard input if - or no ﬁlename is given) is optionally passed through the C preprocessor with the following symbols deﬁned, based on the capabilities of the server being used:SERVERHOST=hostnamethe hostname portion of the display to which you are connected.SRVR_namethe SERVERHOST hostname string turned into a legal identiﬁer.For example, "my-" becomes SRVR_my_dpy_lcs_mit_edu.HOST=hostnamethe same as SERVERHOST.DISPLAY_NUM=numthe number of the display on the server host.CLIENTHOST=hostnamethe name of the host on which xrdb is running.CLNT_namethe CLIENTHOST hostname string turned into a legal identiﬁer.For example, ""becomes CLNT_expo_lcs_mit_edu.RELEASE=numthe vendor release number for the server.The interpretation of this number will vary dependingon VENDOR.REVISION=numthe X protocol minor version supported by this server (currently 0).VERSION=numthe X protocol major version supported by this server (should always be 11).VENDOR="vendor"a string literal specifying the vendor of the server.VNDR_namethe VENDOR name string turned into a legal identiﬁer.For example, "MIT X Consortium"becomes VNDR_MIT_X_Consortium.EXT_nameA symbol is deﬁned for each protocol extension supported by the server.Each extension stringname is turned into a legal identiﬁer.For example, "X3D-PEX" becomes EXT_X3D_PEX.NUM_SCREENS=numthe total number of screens.SCREEN_NUM=numthe number of the current screen (from zero).BITS_PER_RGB=numthe number of signiﬁcant bits in an RGB color speciﬁcation.This is the log base 2 of the numberof distinct shades of each primary that the hardware can generate.Note that it usually is notrelated to PLANES.CLASS=visualclassone of StaticGray,GrayScale, StaticColor,PseudoColor,TrueColor,DirectColor.This is thevisual class of the root window.CLASS_visualclass=visualidthe visual class of the root window in a form you can#ifdef on. The value is the numeric id of thevisual.COLORdeﬁned only if CLASS is one of StaticColor,PseudoColor,TrueColor,or DirectColor.CLASS_visualclass_depth=numA symbol is deﬁned for each visual supported for the screen.The symbol includes the class ofthe visual and its depth; the value is the numeric id of the visual.(If more than one visual has thesame class and depth, the numeric id of the ﬁrst one reported by the server is used.) HEIGHT=numthe height of the root window in pixels.WIDTH=numthe width of the root window in pixels.PLANES=numthe number of bit planes (the depth) of the root window.X_RESOLUTION=numthe x resolution of the screen in pixels per meter.Y_RESOLUTION=numthe y resolution of the screen in pixels per meter.SRVR_name,CLNT_name,VNDR_name,and EXT_name identiﬁers are formed by changing all charac-ters other than letters and digits into underscores (_).Lines that begin with an exclamation mark (!) are ignored and may be used as comments.Note that since xrdb can read from standard input, it can be used to the change the contents of properties directly from a terminal or from a shell script.OPTIONSxrdb program accepts the following options:−help This option (or any unsupported option) will cause a brief description of the allowable options and parameters to be printed.−display displayThis option speciﬁes the X server to be used; see X(7).It also speciﬁes the screen to use for the-screen option, and it speciﬁes the screen from which preprocessor symbols are derived for the-global option.−all This option indicates that operation should be performed on the screen-independent resource property (RESOURCE_MANAGER), as well as the screen-speciﬁc property (SCREEN_RESOURCES) on every screen of the display.For example, when used in conjunc-tion with-query,the contents of all properties are output.For-load,-override and-merge,the input ﬁle is processed once for each screen.The resources which occur in common in the output for every screen are collected, and these are applied as the screen-independent resources.The remaining resources are applied for each individual per-screen property.This the default mode of operation.−global This option indicates that the operation should only be performed on the screen-independent RESOURCE_MANAGER property.−screen This option indicates that the operation should only be performed on the SCREEN_RESOURCES property of the default screen of the display.−screensThis option indicates that the operation should be performed on the SCREEN_RESOURCES property of each screen of the display.For-load,-override and-merge,the input ﬁle is processed for each screen.−n This option indicates that changes to the speciﬁed properties (when used with-load,-override or -merge)or to the resource ﬁle (when used with-edit)should be shown on the standard output, but should not be performed.−quiet This option indicates that warning about duplicate entries should not be displayed.-cppﬁlenameThis option speciﬁes the pathname of the C preprocessor program to be used.Although xrdb was designed to use CPP,any program that acts as a ﬁlter and accepts the -D, -I, and -U options may be used.-nocpp This option indicates that xrdb should not run the input ﬁle through a preprocessor before loading it into properties.−symbolsThis option indicates that the symbols that are deﬁned for the preprocessor should be printed onto the standard output.−query This option indicates that the current contents of the speciﬁed properties should be printed onto the standard output.Note that since preprocessor commands in the input resource ﬁle are part of the input ﬁle, not part of the property,they won’t appear in the output from this option.The−edit option can be used to merge the contents of properties back into the input resource ﬁle without damaging preprocessor commands.−load This option indicates that the input should be loaded as the new value of the speciﬁed properties, replacing whatever was there (i.e.the old contents are removed). This is the default action.−overrideThis option indicates that the input should be added to, instead of replacing, the current contents of the speciﬁed properties.New entries override previous entries.−merge This option indicates that the input should be merged and lexicographically sorted with, instead of replacing, the current contents of the speciﬁed properties.−removeThis option indicates that the speciﬁed properties should be removed from the server.−retain This option indicates that the server should be instructed not to reset if xrdb is the ﬁrst client.This should never be necessary under normal conditions, since xdm and xinit always act as the ﬁrst client.−editﬁlenameThis option indicates that the contents of the speciﬁed properties should be edited into the givenﬁle, replacing any values already listed there.This allows you to put changes that you have madeto your defaults back into your resource ﬁle, preserving any comments or preprocessor lines.−backup stringThis option speciﬁes a sufﬁx to be appended to the ﬁlename used with−edit to generate a backupﬁle.−D name[=value]This option is passed through to the preprocessor and is used to deﬁne symbols for use with con-ditionals such as#ifdef.−U name This option is passed through to the preprocessor and is used to remove any deﬁnitions of this symbol.−I directoryThis option is passed through to the preprocessor and is used to specify a directory to search forﬁles that are referenced with#include.FILESGeneralizes˜/.Xdefaultsﬁles.SEE ALSOX(7), appres(1), listres(1), Xlib Resource Manager documentation, Xt resource documentation ENVIRONMENTDISPLAYto ﬁgure out which display to use.BUGSThe default for no arguments should be to query,not to overwrite, so that it is consistent with other pro-grams.AUTHORSBob Scheiﬂer,Phil Karlton, rewritten from the original by Jim Gettys。

Fedora Linux 系统调用或常用命令详细解析 rngd

NAMErngd − Check and feed random data from hardware device to kernel random deviceSYNOPSISrngd[−b,−−background][−f,−−foreground][−o,−−random-device=ﬁle][−r,−−rng-device=ﬁle][−s,−−random-step=nnn][−W,−−ﬁll-watermark=nnn][−t,−−timeout=nnn][−?,−−help][−V,−−version] DESCRIPTIONThis daemon feeds data from a random number generator to the kernel’s random number entropy pool, after ﬁrst checking the data to ensure that it is properly random.The−f or−−foreground options can be used to tell rngd to avoid forking on startup.This is typically used for debugging. The−f or−−foreground options, which fork and put rngd into the background automati-cally,are the default.The−r or−−rng-device options can be used to select an alternate source of input, besides the default /dev/hwrandom. The−o or−−random-device options can be used to select an alternate entropy output device, besides the default /dev/random. Note that this device must support the Linux kernel /dev/random ioctl API.FIXME: document random-step and timeoutOPTIONS−b,−−backgroundBecome a daemon (default)−f,−−foregroundDo not fork and become a daemon−oﬁle,−−random-device=ﬁleKernel device used for random number output (default: /dev/random)−rﬁle,−−rng-device=ﬁleKernel device used for random number input (default: /dev/hwrandom)−s nnn,−−random-step=nnnNumber of bytes written to random-device at a time (default: 64)−W n,−−ﬁll−watermark=nnnOnce we start doing it, feed entropy to random-device until at leastﬁll-watermark bits of entropyare available in its entropy pool (default: 2048).Setting this too high will cause rngd to dominatethe contents of the entropy pool. Low values will hurt system performance during entropy starves.Do not setﬁll-watermark above the size of the entropy pool (usually 4096 bits).−t nnn,−−timeout=nnnInterval written to random-device when the entropy pool is full, in seconds, or 0 to disable(default: 60)−?,−−helpGive a short summary of all program options.−V,−−versionPrint program versionAUTHORSPhilipp RumpfJeff Garzik − jgarzik@Matt Sottek。

Fedora Linux 系统调用或常用命令详细解析 rndc-confgen

NAMErndc−confgen − rndc key generation toolSYNOPSISrndc−confgen[−a][−b keysize][−c keyﬁle][−h][−k keyname][−p port][−r randomﬁle][−s address][−t chrootdir][−u user]DESCRIPTIONrndc−confgen generates conﬁguration ﬁles for rndc.It can be used as a convenient alternative to writingthe rndc.confﬁle and the corresponding controls and key statements in named.conf by hand. Alternatively, it can be run with the−a option to set up a rndc.keyﬁle and avoid the need for a rndc.confﬁle and acontrols statement altogether.OPTIONS−aDo automatic rndc conﬁguration. This creates a ﬁle rndc.key in/etc(or whatever sysconfdir wasspeciﬁed as when BIND was built) that is read by both rndc and named on startup. The rndc.keyﬁledeﬁnes a default command channel and authentication key allowing rndc to communicate with namedon the local host with no further conﬁguration.Running rndc−confgen −a allows BIND 9 and rndc to be used as drop−in replacements for BIND 8and ndc,with no changes to the existing BIND 8named.confﬁle.If a more elaborate conﬁguration than that generated by rndc−confgen −a is required, for example ifrndc is to be used remotely,you should run rndc−confgen without the−a option and set up arndc.conf and named.conf as directed.−b keysizeSpeciﬁes the size of the authentication key in bits. Must be between 1 and 512 bits; the default is 128.−c keyﬁleUsed with the−a option to specify an alternate location for rndc.key.−hPrints a short summary of the options and arguments to rndc−confgen.−k keynameSpeciﬁes the key name of the rndc authentication key.This must be a valid domain name. The defaultis rndc−key.−p portSpeciﬁes the command channel port where named listens for connections from rndc.The default is953.−r randomﬁleSpeciﬁes a source of random data for generating the authorization. If the operating system does notprovide a/dev/random or equivalent device, the default source of randomness is keyboard input.randomdev speciﬁes the name of a character device or ﬁle containing random data to be used insteadof the default. The special value keyboard indicates that keyboard input should be used.−s addressSpeciﬁes the IP address where named listens for command channel connections from rndc.Thedefault is the loopback address 127.0.0.1.−t chrootdirUsed with the−a option to specify a directory where named will run chrooted. An additional copy ofthe rndc.key will be written relative to this directory so that it will be found by the chrooted named.−u userUsed with the−a option to set the owner of the rndc.keyﬁle generated. If−t is also speciﬁed only theﬁle in the chroot area has its owner changed.EXAMPLESTo allow rndc to be used with no manual conﬁguration, runrndc−confgen −aTo print a sample rndc.confﬁle and corresponding controls and key statements to be manually inserted into named.conf,runrndc−confgenSEE ALSOrndc(8),rndc.conf(5),named(8), BIND 9 Administrator Reference Manual.AUTHORInternet Systems ConsortiumCOPYRIGHTCopyright © 2004, 2005, 2007, 2009 Internet Systems Consortium, Inc. ("ISC")Copyright © 2001, 2003 Internet Software Consortium.。

个人常用的linux命令（redhatfedora）

个人常用的linux命令（redhatfedora）以下命令都是以root身份输入的1.从图形界面进入问文本界面：init 32.从文本界面进入图形界面：startx3.从普通用户进入root用户：su4.进入文件夹：cd /文件路径5.返回上一个文件夹：cd ..6.查看当前位置的文件以及文件夹：ls7.查看当前位置所在的路径：pwd8.复制文件：cp 文件名 /新的文件夹的路径9.打开文件：cat 文件名10.删除文件: rm 文件名11.编辑文件：vi/vim 文件名i 编辑文件n 往下翻页浏览字符（或文件名）向上搜索字符（或文件名）/字符（或文件名）向下搜索字符（或文件名）：输入命令q 退出q! 强制退出wq 保存退出set nu 显示代码的行数0 光标移动到文本开始$ 光标移动到文本末尾12.复制文件夹：cp -r 文件夹 /新的文件夹的路径13.覆盖已存在文件夹及同名和不同名子文件（2步）：rm -rf 已存在文件夹\cp -rf 文件夹 /新的文件夹的路径（不带提示）13.覆盖已存在文件夹及同名在文件，保留不同命文件：\cp -rf 文件夹 /新的文件夹的路径（不带提示）13.新建文件夹：mkdir 文件夹名14.移动文件夹：mv 文件夹新的文件夹的路径15.给文件重命名：mv 旧文件名新文件名（新的名字）16.删除文件夹：rmdir 文件夹17.删除文件夹及子文件(带提示)：rm -r 文件夹18.删除文件夹及子文件（不带提示）：rm -rf 文件夹19.查找某一个文件夹或者文件：find / -name \文件夹名或者文件名 -print20.挂载光驱：mount /dev/cdrom /mnt21.取消挂载光驱：umount /dev/cdrom22.重启Linux：reboot23.关机Linux:shutdown -h now24.make TX44B0_config 软连接（类似于创建快捷方式）make distclean 删除所有原来已编译过的文件make 编译25.tar.gz解压命令：tar -zxvf …….tar.gztar.bz2解压命令:tar -jxvf …….tar.bz2。

Fedora系统介绍几及常用指令

Fedora系统介绍几及常用指令一、FC12系统目录结构简介/：系统根目录。

/bin/：系统启动时需要的执行文件所在目录。

/boot/：系统启动目录。

/boot/grub/grub.conf：启动脚本目录文件。

/dev/：设备目录。

/dev/hda1：硬盘设备文件。

/dev/mapper/：LVM设备所在目录。

/dev/null：空设备。

/dev/sda1：usb设备文件。

/dev/ttyS1：串口设备文件。

/etc/：系统配置。

/etc/crontab：定时启动配置文件。

/etc/exports：NFS服务目录配置文件。

/etc/fstab：启动时自动挂载目录配置文件。

/etc/group：用户组信息文件。

/etc/init.d/：系统启动服务软件所在目录。

/etc/inittab：系统启动配置文件。

/etc/mtab：当前挂载目录信息文件（参见mount命令）。

/etc/ntp.conf：NTP服务配置文件/etc/resolv.conf：域名服务器配置文件。

/etc/rc.local：链接文件，链接到/etc/rc.d/rc.local。

/etc/rc.d/rc.local：启动脚本文件。

/etc/samba/f：SAMBA服务配置文件/etc/selinux/config：SELINUX防火墙配置文件。

/etc/sysconfig/i18n：系统字符集文件/etc/sysconfig/network-scripts/ifcfg-ethX：网卡配置文件。

/etc/udev/rules.d/70-persistent-net.rules：网卡配置文件。

/etc/X11/xorg.conf：显示设备及显示格式配置文件。

非必须存在。

/etc/yum.conf：yum服务配置文件。

/figure/：风格自建目录。

对于服务器，通常会分配一个独立的分区；对于虚拟机，建议把它作为一个软链接，链到共享文件夹。

fedora命令

useradd
1.作用
useradd命令用来建立用户帐号和创建用户的起始目录，使用权限是超级用户。

2.格式
useradd [－d home] [－s shell] [－c comment] [－m [－k template]] [－f inactive] [－e expire ] [－p passwd]
[－r] name
3.主要参数
－c：加上备注文字，备注文字保存在passwd的备注栏中。

－d：指定用户登入时的启始目录。

－D：变更预设值。

－e：指定账号的有效期限，缺省表示永久有效。

－f：指定在密码过期后多少天即关闭该账号。

－g：指定用户所属的群组。

－G：指定用户所属的附加群组。

－m：自动建立用户的登入目录。

－M：不要自动建立用户的登入目录。

－n：取消建立以用户名称为名的群组。

－r：建立系统账号。

－s：指定用户登入后所使用的shell。

－u：指定用户ID号。

4.说明
useradd可用来建立用户账号，它和adduser命令是相同的。

账号建好之后，再用passwd设定账号的密码。

使用useradd命令所建立的账号，实际上是保存在/etc/passwd文本文件中。

5.应用实例
建立一个新用户账户，并设置ID：
＃useradd caojh －u 544
需要说明的是，设定ID值时尽量要大于500，以免冲突。

因为Linux安装后会建立一些特殊用户，一般0
到499之间的值留给bin、mail这样的系统账号。

Fedora Linux 系统调用或常用命令详细解析 rmmod

COPYRIGHT
This manual page Copyright 2002, Rusty Russell, IBM Corporation.
SEE ALSO
modprobe(8), insmod(8), lsmod(8)
2002-12D(8)
NAME
rmmod − simple program to remove a module from the Linux Kernel
SYNOPSIS
rmmod [ -f ] [ -w ] [ -s ] [ -v ] [ modulename ]
DESCRIPTION
rmmod is a trivial program to remove a module from the kernel. Most users will want to use modprobe(8) with the -r option instead.
OPTIONS
-v --verbose Print messages about what the program is doing. Usually rmmod prints messages only if something goes wrong. -f --force This option can be extremely dangerous: it has no effect unless CONFIG_MODULE_FORCE_UNLOAD was set when the kernel was compiled. With this option, you can remove modules which are being used, or which are not designed to be removed, or have been marked as unsafe (see lsmod(8)). -w --wait Normally, rmmod will refuse to unload modules which are in use. With this option, rmmod will isolate the module, and wait until the module is no longer used. Nothing new will be able to use the module, but it’s up to you to make sure the current users eventually ﬁnish with it. See lsmod(8)) for information on usage counts. -s --syslog Send errors to syslog instead of standard error. -V --version Show version of program and exit.

xrandr原理

xrandr原理xrandr 是 X Window System 中用于对显示器进行配置和管理的命令行工具。

它允许用户控制显示器分辨率、刷新率、方向和位置等参数的调整。

xrandr 是一种非常强大的工具，它可以帮助用户在 X 窗口系统中灵活地管理多显示器设置。

xrandr 的原理与 X Window System 的架构密切相关。

X Window System 是一种图形用户界面（GUI）系统，可以在多种操作系统上运行，如Linux，Unix和BSD等。

它由 X 服务器和 X 客户端组成。

X 服务器即运行在显示器上的软件，负责与计算机的硬件，如图形适配器和显示器进行通信。

而 X 客户端则是运行在计算机上的软件，负责创建和管理图形界面。

当用户运行 xrandr 命令时，该命令会连接到 X 服务器，并向其发送相关的请求。

X 服务器在接收到这些请求后，会根据请求的内容进行相应的分析和处理。

如果请求是有效的且与系统兼容，X 服务器会尝试对显示器进行相应的配置变更。

如果配置变更成功，X 服务器会将配置结果返回给 xrandr。

xrandr 可以根据这些结果，显示配置变更的信息或者错误信息。

如果配置失败或者被拒绝，xrandr 也会相应地将失败的信息返回给用户。

xrandr 的原理还涉及到硬件驱动程序和 X 服务器对显示器的扩展支持。

不同的显卡和驱动程序提供不同的功能和设置选项。

因此，X 服务器需要根据硬件和驱动的特性，来决定是否支持特定的显示器配置变更。

这也是为什么在一些情况下，xrandr 命令可能无法对显示器进行特定的配置变更的原因。

总的来说，xrandr 是一个强大而灵活的工具，它通过与 X 服务器通信，实现对显示器的配置和管理。

其原理包括发送配置变更请求，与 X 服务器进行交互，处理配置的变更，以及将结果返回给用户。

xrandr 可以帮助用户在 X 窗口系统中轻松地调整和管理多显示器设置，提供更好的使用体验。

Fedora Linux 系统调用或常用命令详细解析 rmid

NAMErmid − The Java RMI Activation System Daemonrmid starts the activation system daemon that allows objects to be registered and activated in a virtual machine (VM).SYNOPSISrmid [options]DESCRIPTIONThe rmid tool starts the activation system daemon. The activation system daemon must be started before activatable objects can be either registered with the activation system or activated in a VM. See the JavaRMI Speciﬁcation@/javase/6/docs/platform/rmi/spec/rmitoc.html and Activation tutorials@/javase/6/docs/technotes/guides/rmi/activation/overview.html for details on how to write programs that use activatable remote objects.The daemon can be started by executing the rmid command, and specifying a security policyﬁle, as fol-lows:rmid −J−Djava.security.policy=rmid.policyNote:When running Sun’s implementation of rmid,by default you will need to specify a security policyﬁle so that rmid can verify whether or not the information in each ActivationGroupDesc is allowed to beused to launch a VM for an activation group. Speciﬁcally,the command and options speciﬁed by the Com-mandEnvironment and any Properties passed to an ActivationGroupDesc’s constructor must now be explic-itly allowed in the security policyﬁle for rmid.The value of the sun.rmi.activation.execPolicy property dic-tates the policy that rmid uses to determine whether or not the information in an ActivationGroupDesc may be used to launch a VM for an activation group.Executing rmid by default*starts the Activator and an internal registry on the default port, 1098, and*binds an ActivationSystem to the name java.rmi.activation.ActivationSystem in this internal registry.To specify an alternate port for the registry,you must specify the−port option when starting up rmid.For example,rmid −J−Djava.security.policy=rmid.policy −port 1099starts the activation system daemon and a registry on the registry’s default port, 1099.Starting rmid frominetd/xinetdAn alternative to starting rmid from the command line is to conﬁgure inetd(Solaris) or xinetd(Linux) tostart rmid on demand.When rmid starts up, it attempts to obtain an inherited channel (inherited from inetd/xinetd)by inv o king the System.inheritedChannel method. If the inherited channel is null or not an instance of java.nio.chan-nels.ServerSocketChannel,then rmid assumes that it was not started by inetd/xinetd,and it starts up asdescribed above.If the inherited channel is a ServerSocketChannel instance, then rmid uses the .ServerSocketobtained from the ServerSocketChannel as the server socket that accepts requests for the remote objects it exports, namely the registry in which the java.rmi.activation.ActivationSystem is bound and thejava.rmi.activation.Activator remote object. In this mode,rmid behaves the same as when it is started from the command line,except:*Output printed to System.err is redirected to a ﬁle. This ﬁle is located in the directory speciﬁed by thejava.io.tmpdir system property (typically/var/tmp or/tmp)with the preﬁx"rmid−err"and the sufﬁx"tmp".*The−port option is disallowed. If this option is speciﬁed,rmid will exit with an error message.*The−log option is required. If this option is not speciﬁed,rmid will exit with an error message.See the man pages for inetd(Solaris) or xinetd(Linux) for details on how to conﬁgure services to be started on demand.OPTIONS−C<someCommandLineOption>Speciﬁes an option that is passed as a command−line argument to each child process (activation group)of rmid when that process is created. For example, you could pass a property to each virtual machinespawned by the activation system daemon:rmid −C−Dsome.property=valueThis ability to pass command−line arguments to child processes can be useful for debugging. For exam-ple, the following command:rmid −C−Djava.rmi.server.logCalls=truewill enable server−call logging in all child VMs.−J<someCommandLineOption>Speciﬁes an option that is passed to the java interpreter running rmid.For example, to specify that rmiduse a policyﬁle named rmid.policy,the−J option can be used to deﬁne the java.security.policy prop-erty on rmid’s command line, for example:rmid −J−Djava.security.policy=rmid.policy−J−Dsun.rmi.activation.execPolicy=<policy>Speciﬁes the policy that rmid employs to check commands and command−line options used to launchthe VM in which an activation group runs. Please note that this option exists only in Sun’s implementa-tion of the Java RMI activation daemon. If this property is not speciﬁed on the command line, the resultis the same as if−J−Dsun.rmi.activation.execPolicy=default were speciﬁed. The possible values of<policy>can be default,<policyClassName>,or none:*default (or if this property is unspeciﬁed)The default execPolicy allows rmid to execute commands with speciﬁc command−line options only ifrmid has been granted permission to execute those commands and options in the security policyﬁle thatrmid uses. Only the default activation group implementation can be used with the default execution pol-icy.rmid launches a VM for an activation group using the information in the group’s registered activation group descriptor,an ActivationGroupDesc.The group descriptor speciﬁes an optional mandEnvironment which includes the command to execute to start the activation group as well as any command line options to be added to the command line. By default,rmid uses the java command found in java.home.The group descriptor also contains properties overrides that are added to the command line as options deﬁned as:−D<property>=<value>The permission com.sun.rmi.rmid.ExecPermission is used to grant rmid permission to execute a com-mand, speciﬁed in the group descriptor’s CommandEnvironment to launch an activation group. The per-mission com.sun.rmi.rmid.ExecOptionPermission is used to allow rmid to use command−line options, speciﬁed as properties overrides in the group descriptor or as options in the CommandEnvironment, when launching the activation group.When granting rmid permission to execute various commands and options, the permissions ExecPer-mission and ExecOptionPermission need to be granted universally (i.e., granted to all code sources). ExecPermissionThe ExecPermission class represents permission for rmid to execute a speciﬁc command to launch an activation group.SyntaxThe name of an ExecPermission is the path name of a command to grant rmid permission to execute. A path name that ends in "/*" indicates all the ﬁles contained in that directory (where "/" is the ﬁle−sepa-rator character,File.separatorChar). A path name that ends with "/−" indicates all ﬁles and subdirecto-ries contained in that directory (recursively). A path name consisting of the special token "<<ALL FILES>>" matches anyﬁle.Note:A path name consisting of a single "*" indicates all the ﬁles in the current directory,while a path name consisting of a single "−" indicates all the ﬁles in the current directory and (recursively) all ﬁles and subdirectories contained in the current directory.ExecOptionPermissionThe ExecOptionPermission class represents permission for rmid to use a speciﬁc command−line option when launching an activation group. The name of an ExecOptionPermission is the value of a command line option.SyntaxOptions support a limited wildcard scheme. An asterisk signiﬁes a wildcard match, and it may appear as the option name itself (i.e., it matches any option), or an asterisk may appear at the end of the option name only if the asterisk follows either a "." or "=".For example: "*" or "−Dfoo.*" or "−Da.b.c=*" is valid, "*foo" or "−Da*b" or "ab*" is not.Policyﬁle forrmid When granting rmid permission to execute various commands and options, the permissions ExecPermission and ExecOptionPermission need to be granted universally (i.e., granted to all code sources). It is safe to grant these permissions universally because only rmid checks these permis-sions.An example policyﬁle that grants various execute permissions to rmid is:grant {permission com.sun.rmi.rmid.ExecPermission"/ﬁles/apps/java/jdk1.2.2/solaris/bin/java";permission com.sun.rmi.rmid.ExecPermission"/ﬁles/apps/java/jdk1.2.2/solaris/bin/java_g";permission com.sun.rmi.rmid.ExecPermission"/ﬁles/apps/rmidcmds/*";permission com.sun.rmi.rmid.ExecOptionPermission"−Djava.security.policy=/ﬁles/policies/group.policy";permission com.sun.rmi.rmid.ExecOptionPermission"−Djava.security.debug=*";permission com.sun.rmi.rmid.ExecOptionPermission"−Dsun.rmi.*";};The ﬁrst two permissions granted allow rmid to execute the 1.2.2 version of the java and java_g com-mands, speciﬁed by their explicit path names. Note that by default, the version of the java command found in java.home is used (the same one that rmid uses), and does not need to be speciﬁed in the pol-icyﬁle. The third permission allows rmid to execute any command in the directory/ﬁles/apps/rmid-cmds.The fourth permission granted, an ExecOptionPermission,allows rmid to launch an activation group that deﬁnes the security policyﬁle to be/ﬁles/policies/group.policy.The next permission allows the java.security.debug property to be used by an activation group. The last permission allows any property in the sun.rmi property name hierarchy to be used by activation groups.To start rmid with a policyﬁle, the java.security.policy property needs to be speciﬁed on rmid’s com-mand line, for example:rmid −J−Djava.security.policy=rmid.policy**<policyClassName>If the default behavior is not ﬂexible enough, an administrator can provide, when starting rmid,the name of a class whose checkExecCommand method is executed in order to check commands to be executed by rmid.The policyClassName speciﬁes a public class with a public, no−argument constructor and an implemen-tation of the following checkExecCommand method:public void checkExecCommand(ActivationGroupDesc desc,String[] command)throws SecurityException;Before launching an activation group,rmid calls the policy’s checkExecCommand method, passing it the activation group descriptor and an array containing the complete command to launch the activation group. If the checkExecCommand throws a SecurityException,rmid will not launch the activation group and an ActivationException will be thrown to the caller attempting to activate the object.*noneIf the sun.rmi.activation.execPolicy property value is "none", then rmid will not perform any validation of commands to launch activation groups.−log dirSpeciﬁes the name of the directory the activation system daemon uses to write its database and associ-ated information. The log directory defaults to creating a directory,log,in the directory in which thermid command was executed.−port portSpeciﬁes the port rmid’s registry uses. The activation system daemon binds the ActivationSystem,withthe name java.rmi.activation.ActivationSystem,in this registry.Thus, the ActivationSystem on the localmachine can be obtained using the following Naming.lookup method call:import java.rmi.*;import java.rmi.activation.*;ActivationSystem system; system = (ActivationSystem)Naming.lookup("//:port/java.rmi.activation.ActivationSystem");−stopStops the current invocation of rmid,for a port speciﬁed by the−port option. If no port is speciﬁed, itwill stop the rmid running on port 1098.ENVIRONMENT V ARIABLESCLASSPATHUsed to provide the system a path to user−deﬁned classes. Directories are separated by colons. Forexample:.:/usr/local/java/classesSEE ALSOrmic, CLASSPATH, java。

opcontrol_LINUX技术专题之FEDORA专家命令

NAMEopcontrol − control OProﬁle proﬁlingSYNOPSISopcontrol[options]DESCRIPTIONopcontrol can be used to start proﬁling, end a proﬁling session, dump proﬁle data, and set up the proﬁling parameters.OPTIONS--help Show help message.--versionShow version.--list-eventsShows the monitorable events.--init Load the OProﬁle module if required and make the OProﬁle driver interface available.--setup Followed by list options for proﬁling setup. Store setup in ˜root/.oproﬁle/daemonrc. Optional.--statusShow conﬁguration information.--start-daemonStart the oproﬁle daemon without starting proﬁling. Not available in 2.2/2.4 kernels.--start Start data collection with either arguments provided by --setup or with information saved in ˜root/.oproﬁle/daemonrc.--dumpForce a ﬂush of the collected proﬁling data to the daemon.--stop Stop data collection. Not available in 2.2/2.4 kernels.--shutdownStop data collection and kill the daemon.--reset Clear out data from current session, but leaves sav e d sessions.--save=sessionnameSave data from current session to sessionname.--deinitShut down daemon. Unload the oproﬁle module and oproﬁlefs.--session-dir=dir_pathUse sample database out of directory dir_path instead of the default location (/var/lib/oproﬁle).--buffer-size=numSet kernel buffer to num samples. When using a 2.6 kernel buffer watershed need to be tweakedwhen changing this value.--buffer-watershed=numSet kernel buffer watershed to num samples (2.6 only). When it’ll remain only buffer-size - buffer-watershed free entry in the kernel buffer data will be ﬂushed to daemon, most usefull value are inthe range [0.25 - 0.5] * buffer-size.--cpu-buffer-size=numSet kernel per cpu buffer to num samples (2.6 only). If you proﬁle at high rate it can help toincrease this if the log ﬁle show excessive count of sample lost cpu buffer overﬂow.--event=[event|"default"]Specify an event to measure for the hardware performance counters, or "default" for the defaultev e nt. The event is of the form "CPU_CLK_UNHALTED:30000:0:1:1" where the numeric valuesare count, unit mask, kernel-space counting, user-space counting, respectively.Note that this over-rides all previous events selected; if you want two or more counters used simultaneously,you mustspecify them on the same opcontrol invocation.--separate=[none,lib,kernel,thread,cpu,all]Separate samples based on the given separator.’lib’ separates dynamically linked library samplesper application. ’kernel’ separates kernel and kernel module samples per application; ’kernel’implies ’library’. ’thread’ gives separation for each thread and task.’cpu’ separates for each CPU.’all’ implies all of the above options and ’none’ turns off separation.--callgraph=#depthEnable callgraph sample collection with a maximum depth. Use 0 to disable callgraph proﬁling.This option is available on x86 using a 2.6+ kernel with callgraph support enabled.It is also avail-able on PowerPC using a 2.6.17+ kernel.--image=[name,name...|"all"]Only proﬁle the given absolute paths to binaries, or "all" to proﬁle everything (the default).--vmlinux=ﬁlevmlinux kernel image.--no-vmlinuxUse this when you don’t hav e a kernel vmlinux ﬁle, and you don’t want to proﬁle the kernel.--verboseBe verbose in the daemon log. This has a high overhead.--kernel-range=start,endSet kernel range vma address in hexadecimal.OPTIONS (speciﬁc to Xen)--xen=ﬁleXen image--active-domains=<list>List of domain ids participating in a multi-domain proﬁling session. If more than one domain isspeciﬁed in <list> they should be separated using commas. This option can only be used in domain0which is the only domain that can coordinate a multi-domain proﬁling session. Including domain0in the list of active domains is optional. (e.g. --active-domains=2,5,6 and --active-domains=0,2,5,6 are equivalent)ENVIRONMENTNo special environment variables are recognised by opcontrol.FILES/root/.oproﬁle/daemonrcConﬁguration ﬁle for opcontrol/var/lib/oproﬁle/samples/The location of the generated sample ﬁles.VERSIONThis man page is current for oproﬁle-0.9.6.SEE ALSO/usr/share/doc/oproﬁle-0.9.6/, oproﬁle(1)。

fedora 格式化分区

fedora 格式化分区在使用Linux操作系统时，对于磁盘分区的管理是一项必不可少的任务。

而在Fedora操作系统中，格式化分区是一个常见的操作。

本文将介绍Fedora中如何进行格式化分区的操作。

首先，我们需要明确一点，格式化分区是指将存储设备（如硬盘）划分成不同的逻辑分区，并在每个分区中创建文件系统。

格式化分区的目的是为了使操作系统能够将数据存储在分区中，并对其进行读写操作。

在Fedora中，我们可以使用命令行工具或者图形界面来进行格式化分区的操作。

下面将分别介绍这两种方式。

一、命令行方式1. 打开终端，进入命令行界面。

2. 输入命令“sudo fdisk -l”来查看当前系统的磁盘和分区信息。

通过这个命令，我们可以获取到需要格式化的分区的设备号，如/dev/sda1。

3. 输入命令“sudo mkfs.ext4 /dev/sda1”来对分区进行格式化。

这里以ext4文件系统为例，你也可以选择其他的文件系统。

4. 系统会提示你是否要继续进行格式化分区的操作，如果确定，请输入y并按下回车键。

系统将开始进行格式化分区的操作。

5. 格式化完成后，你可以使用命令“sudo mount /dev/sda1 /mnt”将分区挂载到指定的目录。

这里我们将分区挂载到/mnt目录下，你也可以选择其他目录。

6. 至此，你已经成功地完成了格式化分区的操作。

二、图形界面方式1. 打开“文件”应用程序。

2. 在左侧的侧边栏中，选择“其他位置”。

3. 在弹出的对话框中，选择需要进行格式化的分区。

4. 右键点击选中的分区，在弹出的菜单中选择“格式化”选项。

5. 在弹出的对话框中，选择文件系统类型（如ext4）并点击“格式化”按钮。

6. 系统将开始进行格式化分区的操作，并在完成后自动将分区挂载到指定的目录。

无论是使用命令行工具还是图形界面，都可以方便地进行格式化分区的操作。

但在操作之前，请务必备份重要的数据，以免造成数据丢失。

xwud_FEDORA_LINUX_命令解析

NAMExwud - image displayer for XSYNOPSISxwud[−inﬁle][−noclick] [−geometry geom][−display display][−new] [−std <maptype>] [−raw] [−vis <vis-type-or-id>] [−scale] [−help] [−rv] [−plane number][−fg color][−bg color][−dumpheader] DESCRIPTIONXwud is an X Window System image undumping utility.Xwud allows X users to display in a window an image saved in a specially formatted dump ﬁle, such as produced by xwd(1).OPTIONS−bg colorIf a bitmap image (or a single plane of an image) is displayed, this option can be used to specifythe color to display for the "0" bits in the image.−display displayThis option allows you to specify the server to connect to; see X(7).−dumpheaderThis option prints out the XWD header information only.Nothing is displayed.−fg colorIf a bitmap image (or a single plane of an image) is displayed, this option can be used to specifythe color to display for the "1" bits in the image.−geometry geomThis option allows you to specify the size and position of the window. Typically you will onlywant to specify the position, and let the size default to the actual size of the image.−help Print out a short description of the allowable options.−inﬁle This option allows the user to explicitly specify the input ﬁle on the command line.If no input ﬁle is given, the standard input is assumed.−new This option forces creation of a new colormap for displaying the image.If the image characteris-tics happen to match those of the display,this can get the image on the screen faster,but at thecost of using a new colormap (which on most displays will cause other windows to go techni-color).−noclickClicking any button in the window will terminate the application, unless this option is speciﬁed.Termination can always be achieved by typing ’q’, ’Q’, or ctrl-c.−plane numberYou can select a single bit plane of the image to display with this option.Planes are numberedwith zero being the least signiﬁcant bit.−raw This option forces the image to be displayed with whatever color values happen to currently exist on the screen.This option is mostly useful when undumping an image back onto the same screenthat the image originally came from, while the original windows are still on the screen, andresults in getting the image on the screen faster.−rv If a bitmap image (or a single plane of an image) is displayed, this option forces the foreground and background colors to be swapped. This may be needed when displaying a bitmap imagewhich has the color sense of pixel values "0" and "1" reversed from what they are on your dis-play.−scale Allow the window to be resized, and scale the image to the size of the window.−std maptypeThis option causes the image to be displayed using the speciﬁed Standard Colormap.The prop-erty name is obtained by converting the type to upper case, prepending "RGB_", and appending"_MAP". Typical types are "best", "default", and "gray".See xstdcmap(1)for one way of creat-ing Standard Colormaps.−vis vis-type-or-idThis option allows you to specify a particular visual or visual class.The default is to pick the"best" one.A particular class can be speciﬁed: "StaticGray", "GrayScale", "StaticColor", "Pseu-doColor", "DirectColor", or "TrueColor". Or"Match" can be speciﬁed, meaning use the sameclass as the source image.Alternatively,an exact visual id (speciﬁc to the server) can be speci-ﬁed, either as a hexadecimal number (preﬁxed with "0x") or as a decimal number.Finally,"default" can be speciﬁed, meaning to use the same class as the colormap of the root window.Case is not signiﬁcant in any of these strings.ENVIRONMENTDISPLAYTo get default display.FILESXWDFile.hX Window Dump File format deﬁnition ﬁle.BUGSxwud doesn’t handle big/deep images very well on servers that don’t hav e the BIG-REQUESTS extension. SEE ALSOxwd(1), xstdcmap(1), X(7)AUTHORBob Scheiﬂer,MIT X Consortium。

操作学习笔记之Linux之Fedora

操作系统学习笔记Linux之Fedora序言Fedora是一款由Fedora基金会管理和控制的Linux发行版本，当然，背后有金主爸爸RedHat的支持。

因此操作系统Fedora与RedHat Enterprise Linux有这样一层关系，即Fedora 在半年一次的版本中推出新功能，由广大社区用户验证后，再由RedHat将这些功能放到新发行的RedHat Enterprise Linux版本中，然后卖给企业用户。

当然，由于Linux采用GPL协议，因此RedHat能收取服务费。

虽然Fedora通常每半年推出一个版本，例如当前版本31就是在2019年10月底发布的，但其实每个版本又有细分，比如常见的Server版和Workstation版，而根据桌面不同，还有Cinnamon、KDE、LXDE、LXQt、MATE_Compiz、SoaS、Xfce等版本。

由于本人之前基本在Windows环境下工作，故此对Fedora确实不够熟悉，文中如出现谬误，还望海涵。

另由于本文过审，不允许出现邮件地址，因此文中的“®”均请替换成“@”。

一、初识Fedora1.操作系统版本的选择本文选择Fedora 31作为学习对象，由于目前官网已不再提供32位版本，因此只有64位版本可用。

涉及的细分版本包括Workstation、KDE、Cinnamon、MA TE_Compiz、Xfce、Server等6款。

虽然这些安装镜像通过Fedora官网就可以获得，但国内网络大家都懂的，因此我选择通过网易镜像站完成下载工作，各镜像的下载地址如下：Workstation版：/fedora/releases/31/Workstation/x86_64/iso/Fedora-Workstation-Live-x86_64-31-1.9.isoKDE版：/fedora/releases/31/Spins/x86_64/iso/Fedora-KDE-Live-x86_64-31-1.9.isoCinnamon版：/fedora/releases/31/Spins/x86_64/iso/Fedora-Cinnamon-Live-x86_64-31-1.9.isoMATE版：/fedora/releases/31/Spins/x86_64/iso/Fedora-MATE_Compiz-Live-x86_64-31-1.9.isoXfce版：/fedora/releases/31/Spins/x86_64/iso/Fedora-Xfce-Live-x86_64-31-1.9.isoServer版：/fedora/releases/31/Server/x86_64/iso/Fedora-Server-dvd-x86_64-31-1.9.iso其中Workstation版和Server版都在各自的目录下，比较好找，其他桌面版本则统一放在/fedora/releases/31/Spins目录下面，还需要其他版本的可以到里边找找。