Remove lines from a file: Difference between revisions
→{{header|PowerShell}}
m (added a ;Task: (bold) header.) |
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Line 1,402:
del-line "foobar.txt" 1 2
</lang>
=={{header|PureBasic}}==
<lang PureBasic>
; Contents of file 'input.txt' before deletion of lines :
;
; cat
; dog
; giraffe
; lion
; mouse
; pig
; tiger
; zebra
EnableExplicit
#Output$ = "output.txt"; insert path to temporary output file
Procedure RemoveLines(Input$, StartLine, NbLines)
Protected lineCount = 0
Protected endline = StartLine + NbLines - 1
Protected row$
If Not ReadFile(0, Input$)
PrintN("Error opening input file")
ProcedureReturn
EndIf
If Not CreateFile(1, #Output$)
PrintN("Error creating output file")
CloseFile(0)
ProcedureReturn
EndIf
While Not Eof(0)
row$ = ReadString(0)
lineCount + 1
If lineCount < StartLine Or lineCount > endLine
WriteStringN(1, row$)
EndIf
Wend
If endLine > lineCount
PrintN("Attempted to remove lines beyond the end of the file")
; but still allow removal of lines (if any) up to the end of the file
EndIf
CloseFile(0)
CloseFile(1)
If Not DeleteFile(Input$)
PrintN("Unable to delete input file so output file can be renamed")
ProcedureReturn
EndIf
If Not RenameFile(#Output$, Input$)
PrintN("Unable to rename output file")
EndIf
EndProcedure
Define fInput$
If OpenConsole()
; delete lines 2,3 amnd 4 of 'input.txt'
fInput$ = "input.txt"; insert path to input file
RemoveLines(fInput$, 2, 3)
PrintN("")
PrintN("Press any key to close the console")
Repeat: Delay(10) : Until Inkey() <> ""
CloseConsole()
EndIf
</lang>
{{out|Output ('input.txt' after removal of lines}}
<pre>
cat
mouse
pig
tiger
zebra
</pre>
=={{header|Python}}==
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