Difference between revisions of "PERL/C3/File-Handling/Gujarati"
From Script | Spoken-Tutorial
Jyotisolanki (Talk | contribs) |
Jyotisolanki (Talk | contribs) |
||
| Line 75: | Line 75: | ||
|- | |- | ||
| − | | પ્રથમ આપણે એક ટેક્સ્ટ ફાઈલ બનાવીશું અને તેમાં અમુક ડેટા સંગ્રહીશું.ટર્મિનલ પર જાવ અને ટાઈપ કરો '''gedit first.txt''' અને એન્ટર દબાવો. | + | | 01:38 |
| + | | પ્રથમ આપણે એક ટેક્સ્ટ ફાઈલ બનાવીશું અને તેમાં અમુક ડેટા સંગ્રહીશું.ટર્મિનલ પર જાવ અને ટાઈપ કરો '''gedit || first.txt''' અને એન્ટર દબાવો. | ||
|- | |- | ||
Revision as of 12:17, 22 January 2016
| Time | Narration | |
| 00:01 | PERL. માં File Handling પરના આ સ્પોકન ટ્યુટોરીયલમાં સ્વાગત છે. | |
| 00:06 | આ ટ્યુટોરીયલમાં આપણે આપણે શીખીશું:
| |
| 00:17 | આ ટ્યુટોરીયલ માટે હું ઉપયોગ કરી રહી છું:
| |
| 00:28 | તમે તમારી પસંદગી અનુસાર કોઈ પણ ટેક્સ્ટ એડિટર વાપરી શકો છો. | |
| 00:32 | આ ટ્યુટોરીયલના અનુસરણ માટે તમને ' Perl પ્રોગ્રામિંગ વિષે સામાન્ય જાણકારી હોવી જોઈએ. | |
| 00:37 | જો નથી તો સ્પોકન ટ્યુટોરિયલ વેબ સાઈટ પર ઉપલબ્ધ Perl ટ્યુટોરિયલ જુઓ. | |
| 00:43 | મૂળભૂત ઓપરેશન જે આપણે પર્લમાં ફાઈલ્સ સાથે કરી શકીએ છીએ તે છે:
| |
| 00:54 | file handles are: મૂળભૂત file handles છે.
| |
| 01:02 | આ open ફંકશન માટે સિન્ટેક્સ છે. | |
| 01:05 | સિન્ટેક્સમાં FILEHANDLE એ ફાઈલ હેન્ડલ છે જે open ફંકશન થી રીટર્ન થાય છે. | |
| 01:11 | MODE ફાઈલ ખોલવું જેવા: રીડ, રાઈટ વગેરે મોડ ને બતાડે છે. | |
| 01:18 | EXPR એ ભૌતિક ફાઈલનનું નામ છે જે વાંચવા અને લખવામાં ઉપયોગ થાય છે. | |
| 01:27 | અહી પ્રદશિતની જેમ open ફંકશન ને લખવા માટે અન્ય માર્ગ છે. | |
| 01:32 | ચાલો સમઝીએ વર્તમાન ફાઈલને કેવી રીતે ખોલવી અને તેમાંથી ડેટા કેવી રીતે વાંચવા. | |
| 01:38 | પ્રથમ આપણે એક ટેક્સ્ટ ફાઈલ બનાવીશું અને તેમાં અમુક ડેટા સંગ્રહીશું.ટર્મિનલ પર જાવ અને ટાઈપ કરો gedit | first.txt અને એન્ટર દબાવો. |
| 01:51 | first dot txt ફાઈલમાં આપેલ ટેક્સ્ટ ટીપ કરો: | |
| 01:55 | ફાઈલ ને સેવ કરીને gedit બંદ કરો. | |
| 01:59 | હવે આપણે એક Perl પ્રોગ્રામ જોશું જે first.txt ફાઈલ ખોલે છે અને વિષય વસ્તુ વાંચે છે. | |
| 02:07 | હવે હું openfile.pl સેમ્પલ પ્રોગ્રામ ખોલીશ. જે મેં પહેલાથી જ સેવ કરેલ છે. | |
| 02:13 | Type: gedit openfile dot pl ampersand and press Enter. | |
| 02:19 | In the openfile dot pl file, type the following code as displayed on the screen. | |
| 02:25 | Let us understand the code now. | |
| 02:28 | The open function opens a file for reading. | |
| 02:33 | The first parameter DATA is the filehandle which allows Perl to refer to the file in future. | |
| 02:40 | The second parameter “<” less than symbol denotes the READ mode. | |
| 02:44 | If you fail to specify the Mode, by default the file will be opened in “READ” mode. | |
| 02:50 | The third parameter 'first.txt' is the filename from where the data has to be read. | |
| 02:57 | What will happen if the file 'first.txt' does not exist? | |
| 03:02 | The script will die with the appropriate error message, stored in the dollar exclamation ($!)variable. | |
| 03:08 | The while loop will read line by line and loop through the <DATA> file until all the lines have been read. | |
| 03:17 | Print dollar underscore ('$_') variable will print the contents of the current line. | |
| 03:22 | Lastly, close the file with the FILEHANDLE name which we had given in the open statement. | |
| 03:29 | Closing a file prevents any accidental file changes or overwriting of the content. | |
| 03:36 | Now, press Ctrl+S to save the file. | |
| 03:40 | Let us execute the program. | |
| 03:42 | Switch back to the terminal and type perl openfile dot pl and press Enter. | |
| 03:51 | The output is displayed as shown. | |
| 03:54 | This is the same content that we saw earlier in first dot txt file. | |
| 03:59 | Next we will see how to write data into a file. | |
| 04:03 | The open statement with greater than (>) symbol defines the WRITE mode. | |
| 04:08 | Filename represents the name of the file where the data has to be written. | |
| 04:13 | Let me open the sample program 'writefile.pl' which I have already saved. | |
| 04:19 | Switch to the terminal. | |
| 04:21 | Now, type: gedit writefile dot pl ampersand and press Enter. | |
| 04:29 | In the writefile dot pl file, type the following code as displayed on the screen. | |
| 04:34 | Let me explain the code now. | |
| 04:37 | The open function opens a file 'second.txt' in "write" mode. | |
| 04:44 | “>” - Greater than symbol before the filename denotes the "write" mode. | |
| 04:49 | The first parameter "FILE1" is the FILEHANDLE. | |
| 04:53 | The print function prints the given text to FILEHANDLE. i.e 'FILE1'. | |
| 04:59 | Now, press Ctrl+S to save the file. | |
| 05:03 | Let us execute the program. | |
| 05:05 | Switch back to the terminal and type: perl writefile dot pl and press Enter. | |
| 05:12 | Now, let us check whether the text has been written in 'second.txt' file. | |
| 05:18 | Type: gedit second.txt and press Enter. | |
| 05:23 | We can see the text: "Working with files makes data storage and retrieval a simple task!" in our 'second.txt' file. | |
| 05:32 | Let us close the 'second.txt' file. | |
| 05:35 | What will happen if we open the same file again in "write" mode? Let us see that. | |
| 05:41 | In the 'writefile.pl', comment the previous print Statement. | |
| 05:46 | Add the below print command. | |
| 05:48 | Now, press Ctrl+S to save the file. Let us execute the program. | |
| 05:54 | Switch back to the terminal and type perl writefile dot pl and press Enter. | |
| 06:00 | Now, let us check the 'second.txt' file once again. | |
| 06:04 | Type: gedit second.txt and press Enter. | |
| 06:09 | We can see the output: “Greater than symbol (>) overwrites the content of the file!" | |
| 06:14 | The previous contents of the 'second.txt' file has been overwritten. | |
| 06:19 | This is because, we had opened the file in the "write" mode again. | |
| 06:24 | Let us close the 'second.txt' file. | |
| 06:27 | Next, we will see how to append data to an existing file. | |
| 06:32 | The open statement with two greater than (>>) symbols denotes the "APPEND" mode. | |
| 06:38 | Now I will open the writefile dot pl again in gedit. | |
| 06:44 | In the open statement, type two greater (>>) than symbols. This will denote that the file is in append mode. | |
| 06:52 | Comment the previous print statement, as it is already executed. | |
| 06:57 | Add the line: print FILE1 within double quotes "Two greater than symbols (>>) open the file in append mode", to append to the existing data. | |
| 07:07 | Now, press Ctrl+S to save the file. | |
| 07:11 | Let us execute the program. | |
| 07:14 | Switch back to the terminal and type: perl writefile dot pl and press Enter. | |
| 07:20 | Now, let us check whether the text has been appended to the 'second.txt' file. | |
| 07:26 | Type: gedit second.txt and press Enter. | |
| 07:31 | We can see the text has been appended in our 'second.txt' file. | |
| 07:36 | Let us close the 'second.txt' file. | |
| 07:39 | Similarly, there are other modes also. | |
| 07:42 | Try out these options on your own and understand what happens. | |
| 07:49 | This brings us to the end of this tutorial. Let us summarize. | |
| 07:53 | In this tutorial, we learnt to:
| |
| 08:03 | Here is an assignment for you. Change the file attribute to "+>" in the 'writefile.pl' program. | |
| 08:11 | Save and execute the program. | |
| 08:14 | Open the 'second.txt' file to see the output. | |
| 08:17 | Analyze the usage of file attribute "+>". | |
| 08:22 | The video at the following link summarizes the Spoken Tutorial project. Please download and watch it. | |
| 08:29 | The Spoken Tutorial Project team:
| |
| 08:37 | For more details, please write to us. | |
| 08:41 | Spoken Tutorial project is funded by NMEICT, MHRD, Government of India. | |
| 08:48 | More information on this mission is available at this link. | |
| 08:53 | This is Nirmala Venkat from IIT Bombay, signing off. Thanks for watching. |
