LINE INPUT (file statement): Difference between revisions
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(Created page with "The '''LINE INPUT #''' file statement reads an entire line from a text file into a string variable. {{PageSyntax}} : '''LINE INPUT''' '''#'''{{Parameter|fileNumber&}}''',''' ''stringVariable$'' {{Parameters}} * {{Parameter|fileNumber&}} is the INTEGER number of the file previously opened with the OPEN statement. * {{Parameter|stringVariable$}} holds the text line read from the file. {{PageDescription}} * Reads a file using the {{Parameter|fileNumber&}} OP...") |
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| Line 28: | Line 28: | ||
{{PageExamples}} | {{PageExamples}} | ||
''Example:'' Finding the number of filenames listed in a file to dimension an array to hold them. | ''Example:'' Finding the number of filenames listed in a file to dimension an array to hold them. | ||
{{CodeStart}} | {{CodeStart}} | ||
{{Cl|REDIM}} FileArray$(100) 'create {{Cl|$DYNAMIC|dynamic}} array | {{Cl|REDIM}} FileArray$(100) 'create {{Cl|$DYNAMIC|dynamic}} array | ||
{{Cl|SHELL}} {{Cl|_HIDE}} "DIR /B *.* > D0S-DATA.INF" | {{Cl|SHELL}} {{Cl|_HIDE}} "DIR /B *.* > D0S-DATA.INF" | ||
{{Cl|IF...THEN|IF}} {{Cl|_FILEEXISTS}}("D0S-DATA.INF") THEN | {{Cl|IF...THEN|IF}} {{Cl|_FILEEXISTS}}("D0S-DATA.INF") THEN | ||
{{Cl|OPEN}} "D0S-DATA.INF" FOR {{Cl|INPUT (file mode)|INPUT}} AS #1 | {{Cl|OPEN}} "D0S-DATA.INF" FOR {{Cl|INPUT (file mode)|INPUT}} AS #1 | ||
DO UNTIL {{Cl|EOF}}(1) | DO UNTIL {{Cl|EOF}}(1) | ||
{{Cl|LINE INPUT}} #1, file$ 'read entire text file line | {{Cl|LINE INPUT}} #1, file$ 'read entire text file line | ||
| Line 40: | Line 40: | ||
{{Cl|END IF}} | {{Cl|END IF}} | ||
{{Cl|REDIM}} FileArray$(filecount%) | {{Cl|REDIM}} FileArray$(filecount%) | ||
{{Cl|PRINT}} filecount% | {{Cl|PRINT}} filecount% | ||
{{CodeEnd}} | {{CodeEnd}} | ||
Revision as of 01:57, 23 January 2023
The LINE INPUT # file statement reads an entire line from a text file into a string variable.
Syntax
- LINE INPUT #fileNumber&, stringVariable$
- fileNumber& is the INTEGER number of the file previously opened with the OPEN statement.
- stringVariable$ holds the text line read from the file.
Description
- Reads a file using the fileNumber& OPENed in the INPUT (file mode) or BINARY file mode as one file line text string.
- NOTE: LINE INPUT will work faster in BINARY mode than in INPUT mode.
- Using LINE INPUT # in BINARY mode is possible in version 1.000 and up
- Can be used with EOF to count the number of lines of data (records) in a file using a loop.
- Use the EOF function to avoid going past the end of a file and creating an error.
- LINE INPUT # can even retain the original quotation marks in text.
- Note: QB64 will not remove CHR$(0) from the end of LINE INPUT # string return values like QBasic did.
- If an "Input past End of file" error occurs, check for CHR$(26) (end of file character) in the files being read.
- Warning: files must exist to be opened in INPUT mode. Use _FILEEXISTS to avoid program errors.
Examples
Example: Finding the number of filenames listed in a file to dimension an array to hold them.
REDIM FileArray$(100) 'create dynamic array SHELL _HIDE "DIR /B *.* > D0S-DATA.INF" IF _FILEEXISTS("D0S-DATA.INF") THEN OPEN "D0S-DATA.INF" FOR INPUT AS #1 DO UNTIL EOF(1) LINE INPUT #1, file$ 'read entire text file line filecount% = filecount% + 1 LOOP CLOSE #1 END IF REDIM FileArray$(filecount%) PRINT filecount% |
See also
- OPEN, CLOSE
- INPUT (file mode), INPUT #, INPUT$ (file input)
- INPUT, LINE INPUT, INPUT$ (keyboard input)
- _FILEEXISTS, _DIREXISTS
- FILELIST$ (member-contributed function replacement for FILES)