Programming and Data Structures by Pearson

462 Programming and Data Structures

fp=fopen(argo{l],nr");

if(fp = N U L L )

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printf ( “File N ot Found");

exit(l);

)

*p=fopen(argv[2],”r");

if (s p = N U L L )

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fcloseallO;

rename(argv[l],argv[2]);

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else

printf ("Duplicate file name or file is in use." );

return 0;

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Explanation In the above program the main () receives two file names. Existence of old file is

checked through read mode. If the file does not exist the program terminates. On the other hand if

the second file exists the rename operation can not be done. If the file pointer of second file contains

N

ULL value then only rename operation is performed otherwise program termina ...