Apache Web Hosting, Affordable, PHP5, Comcast - Linux Blog

Chapter 4 . Processing Text 175 The cat utility can also be used to display the contents of a text file. These utilities aren t filters but are often helpful when working with them. Deleting or substituting characters There are times when you may want to search a document for specific characters and then either delete or replace them. An example of this use would be a document that contains both uppercase and lowercase characters, but you would prefer all characters to be lowercase. The tr utility provides this functionality using the following syntax: tr option set1 set2 The options used with tr are shown in Table 4-7. Table 4-7 Options Used with tr Option Use -s Replaces a sequence of characters with one character. –help Displays help information and then exits. –version Displays version information and then exits. -d Deletes the characters specified. The following is an example of the use of the tr utility. First, the contents of the file are viewed using the more utility. The file contains a mixture of both uppercase and lowercase characters. In an effort to avoid confusion all uppercase characters are replaced with their lowercase equivalents using the trutility. # more mkdir MyFiles cd MyFiles ls -al MyFiles > AllofMyFiles # tr A-Z a-z < mycommands mkdir myfiles cd myfiles ls -al myfiles > allofmyfiles
We would like to recommend you tested and proved virtual web hosting services, which you will surely find to be of great quality.

174 Part II . Getting Around in Linux Table 4-6 Options Used with fmt Option Use -t Works like the -c option except if the indentation of the second line in a paragraph matches that of the first, the second line is considered to be a one-line paragraph. -s Specifies that lines are only to be split, not joined. -u Specifies that uniform spacing be used; this reduces spacing between all words to one space and spaces between sentences to two spaces. -NUMBER or -w NUMBER Sets the width of lines to the NUMBER specified. -p PREFIX Specifies that only lines beginning with PREFIX are to be formatted. -c Preserves the indentation at the beginning of a paragraph and aligns the paragraph with the left margin of the second line. The fmt utility also preserves blank lines, indentations, and spacing so that any special formatting contained within the document is not changed. An example of the use of the fmt utility is shown below. As you can see in the example, all lines between paragraphs are maintained, and the utility has attempted to produce lines that are all 40 characters wide. # fmt -40 mydoc Linux offers a variety of tools to use for processing and filtering text. These tools enable you to search for data and then manipulate it depending on the tool you use. The tools can be used from the command line or placed in scripts, which are executed to perform the needed tasks. The output is then either sent to standard output, where it can be redirected or piped into another utility, or sent to a file. The flexibility in the input and output of these tools enables you to customize the text for a variety of uses. Regardless of how many filters are run, the original text remains intact. When working with text files you will likely use a pager such as more or less. These utilities are used to display text one page at a time.
In case you need affordable webhost to host your website, our recommendation is ecommerce web host services.

Chapter 4 . Processing Text 173 Michael Craig S Johannes Erdfelt S Thomas McCanta S Joakim Erdfelt S Pete Gizzi M Neil Schroeder S In this example the default setting of eight spaces is used. Because the name Johannes Erdfelt has 16 characters, the tab is expanded to the 24th character field. In the following example, the setting of 9 spaces for the tab field allows the marital status fields to line up evenly. # expand -t 9 marital Scott Bessler S Jason Nash M Angie Nash M Derek Stutsman M Jeff Arellano S Paul Ward M Alex Blauvelt S Peter Anapol M David Goolsby S Michael Craig S Johannes Erdfelt S Thomas McCanta S Joakim Erdfelt S Pete Gizzi M Neil Schroeder S Formatting paragraphs The fmt utility formats each paragraph in a file and sends the output to the standard output. This utility is used to specify the width of lines and joins or separates lines in an effort to produce lines that are all the same length. The fmt utility attempts to separate lines at the end of a sentence. When this isn t possible, it avoids breaking lines after the first word or before the last word of the sentence. Sentences are determined to end with either a period, exclamation, or question mark (.!?) followed by two spaces or a line feed character. The entire paragraph is read before any line breaks are introduced. The default line width used with fmt is 75 characters. The default width can be overwritten using the appropriate option with the fmtutility. Table 4-6 covers some of the options used with this utility.
In case you need affordable webhost to host your website, our recommendation is ecommerce web host services.

172 Part II . Getting Around in Linux Johannes Erdfelt Johan Pete Gizzi Sting David Goolsby Dave Thomas McCanta Thomas Angie Nash Netchick Jason Nash Netjunkie Neil Schroeder Pri Derek Stutsman Zaphod Paul Ward Lordram Converting tabs to spaces When creating a file on Linux the tab function is seen as one key, but the actual tab settings can vary from system to system. This can change the appearance of a file based on the system displaying the file. In order to create a uniform appearance in files, you may want to replace the tabs within a file with a specified number of spaces. This will cause the file to appear the same on all systems. The expand utility is used to expand tabs to spaces. This utility can work with text either in a file or on the standard input. The options for the expand utility are shown in Table 4-5. Table 4-5 Options Used with expand Option Use -t Uses a set of numbers to specify the location of tabs that are to be converted. –help Displays help information and then exits. –version Displays version information and then exits. -I Specifies that only tabs at the beginning of a line are converted. The default action of the expand utility is to convert all tabs within a file to eight spaces. Some examples of the expandutility are the following: # expand marital Scott Bessler Jason Nash M Angie Nash M Derek Stutsman M Jeff Arellano S Paul Ward M Alex Blauvelt S Peter Anapol M David Goolsby S
Searching for affordable and reliable webhost to host and run your web applications? Go to our java web server services and you will be pleased.

Chapter 4 . Processing Text 171 The following is an example of the use of these ranges to output only the first ten characters of each line: # cut -c 1-10 nameslist Scott Bess Jason Nash Angie Nash Derek Stut Jeff Arell Paul Ward Alex Blauv Peter Anap David Gool Michael Cr Johannes E Thomas McC Joakim Erd Pete Gizzi Neil Schro The cut utility can specify bytes, characters, or fields in files to be displayed. Pasting text The paste utility enables you to join text from multiple files. Corresponding lines of the specified file are written to standard output with each line separated by a tab character. The options used with the paste utility are shown in Table 4-4. Table 4-4 Options Used with paste Option Use -d delimit-list Uses the characters specified in delimit-list consecutively instead of the tab character when separating merged files. -s Pastes lines from one file at a time. The following is an example of using the pasteutility: # paste alphanames nicks Peter Anapol Bammage Jeff Arellano Rexmortis Scott Bessler Jackyl Alex Blauvelt Dragonstr Michael Craig Alchemist Joakim Erdfelt Just_joe
You need excellent and relaible webhost company to host your web applications? Then pay a visit to Inexpensive Web Hosting services.

170 Part II . Getting Around in Linux David Goolsby Michael Craig Johannes Erdfelt Thomas McCanta Joakim Erdfelt Pete Gizzi Neil Schroeder # sort +1 +0 nameslist Peter Anapol Jeff Arellano Scott Bessler Alex Blauvelt Michael Craig Joakim Erdfelt Johannes Erdfelt Pete Gizzi David Goolsby Thomas McCanta Angie Nash Jason Nash Neil Schroeder Derek Stutsman Paul Ward The use of these fields allows a great deal of flexibility in sorting lists in files. It is important to remember that the sort utility does not change the original file. Output is sent to the standard output where it can be viewed or redirected to another command or file. Cutting text The cut utility is used to write selected parts of a file to standard output. The cut utility can be used to select columns or fields from specified files. It is possible to select a specific line address, several line addresses, or a range of line addresses. Table 4-3 covers the various options used with the cut utility. Table 4-3 Options Used with cut Option Use -c Outputs only the specified characters. -f Outputs only the specified fields, which are delimited by tabs. -help Displays help and then exits. -b Outputs only the specified bytes range. -version Displays version information and then exits.
If you are looking for cheap and quality webhost to host and run your website check Jboss Web Hosting services.

Chapter 4 . Processing Text 169 41 5 90 bread butter Celestial Seasons Centrum eggs flour ice milk sugar Whiskas In the following example, two sorted files are merged. As you can see, the files are not resorted but are simply combined. #sort -m alphanicks alphanames angie birdgrlmom crystalmoon denise desteve jcfraggle jill judy katrina kim lisa lma loudhouse monica netchickie nikki nikks trinityz It is also possible to sort files based on fields. Fields can be separated by spaces or tabs and are numbered starting at zero. When sorting based on fields, the +symbol precedes the field number with each field being separated by spaces. In the following example, the nameslist file is sorted by the second field (+1) and then by the first field (+0): #cat nameslist Scott Bessler Jason Nash Angie Nash Derek Stutsman Jeff Arellano Paul Ward Alex Blauvelt Peter Anapol
You want to have a cheap webhost for your apache application, then check apache web hosting services.

168 Part II . Getting Around in Linux Table 4-2 Options Used with sort Option Use -c Checks to see whether the file is sorted. -d Considers only alphanumeric characters and sorts in phone directory order. -f Folds lowercase to uppercase characters. -m Merges already sorted files without resorting them. -M Compares sorted files. -n Sorts numerically. -o FILE Writes output to the specified file instead of standard output. -r Reverses the results. –help Displays help and exits. –version Displays version and exits. -b Ignores leading blanks. An example of the use and output of the sort utility is as follows: # sort list 3 32 41 5 90 Celestial Seasons Centrum Whiskas bread butter eggs flour ice milk sugar As you can see in this example, by default, lists are sorted first by numeric order followed by alphabetical order, with capital letters before lowercase. In the following example, the -f option tells sortto ignore case. # sort -f list 3 32
Searching for affordable and proven webhost to host and run your servlet applications? Go to Linux Web Hosting services and you will find it.

Chapter 4 . Processing Text 167 In the The xargs utility is used to feed arguments to another utility at a rate that it can Real World handle. Using this command when it isn t needed won t produce any errors. Modifying Text with Filters Objective 1.3 GNU and Linux Commands Process Text Streams Using Text Processing Filters. Send text files and output streams through text utility filters to modify the output in a useful way. Includes the use of standard unix commands found in the GNU textutils package such as sed, sort, cut, expand, fmt, head, join, nl, od, paste, pr, split, tac, tail, tr, and wc. Perform Searches of Text Files Making Use of Regular Expressions. Includes creating simple regular expressions and using related tools such as grep and sed to perform searches. Linux offers a variety of tools to use for processing and filtering text. These tools enable you to search for data and then manipulate it depending on the tool you use. The tools can be used from the command line or placed in scripts, which are executed to perform the needed tasks. The output is then either sent to standard output, where it can be redirected or piped into another utility, or sent to a file. The flexibility in the input and output of these tools enables you to customize the text for a variety of uses. Regardless of how many filters are run, the original text remains intact. When working with text files you will likely use a pager such as more or less. These utilities are used to display text one page at a time. The cat utility can also be used to display the contents of a text file. These utilities aren t filters but are often helpful when working with them. Sorting lines of a file The sort utility sorts lines of text and displays them to standard output. It is used to sort, merge, and compare lines from files or standard input. This utility is used with the following syntax: sort option filename Table 4-2 lists the options commonly used with the sort utility.
Visit our web design programs services for an affordable and reliable webhost to suit all your needs.

166 Part II . Getting Around in Linux # sort +1 nameslist | tee abcnames | nl > abc123names # more abcnames Peter Anapol Jeff Arellano Scott Bessler Alex Blauvelt Michael Craig Joakim Erdfelt Johannes Erdfelt Pete Gizzi David Goolsby Thomas McCanta Angie Nash Jason Nash Neil Schroeder Derek Stutsman Paul Ward # more abc123names 1 Peter Anapol 2 Jeff Arellano 3 Scott Bessler 4 Alex Blauvelt 5 Michael Craig 6 Joakim Erdfelt 7 Johannes Erdfelt 8 Pete Gizzi 9 David Goolsby 10 Thomas McCanta 11 Angie Nash 12 Jason Nash 13 Neil Schroeder 14 Derek Stutsman 15 Paul Ward xargs The xargs utility is used to pass a large number of arguments to other commands. The xargs utility reads arguments from the standard input, delimited by blanks (the blanks function as normal characters when used with double or single quotes or a backslash) or line feed characters, and executes the command one or more times with any initial arguments followed by arguments read from standard input. Blank lines on the standard input are ignored. This enables a command to process more arguments than it could normally handle. In the following example the locate database is searched, using the locatelink, for all README files. Using xargs, the filenames are then sent to the catutility, which will then display the file contents. All of the text of these files is sent to the fmt utility, which formats the data for the line length of 60 characters. The output is then redirected to the file /home/angie/readmes. locate README | xargs cat | fmt 60 > /home/angie/readmes
From our experience, we can recommend PHP Web Hosting services, if you need affordable webhost to host and run your web application.