i unable to read a text file into my code i have the right code i think i just can not make it run with no errors
tablet 0 Newbie Poster
server_crash 64 Postaholic
i unable to read a text file into my code i have the right code i think i just can not make it run with no errors
can you post the code?
nanosani 20 Technize.net addict Team Colleague
what stream are you using for reading the code .....?
cosi 4 Junior Poster
What are the errors you're getting? When are you getting them? at compile time or run-time?
i unable to read a text file into my code i have the right code i think i just can not make it run with no errors
soniprafull 0 Newbie Poster
Description: C program to test text file reading.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#define CR 13 /* Decimal code of Carriage Return char */
#define LF 10 /* Decimal code of Line Feed char */
#define EOF_MARKER 26 /* Decimal code of DOS end-of-file marker */
#define MAX_REC_LEN 1024 /* Maximum size of input buffer */
/* Read functions */
int T_fscanf(FILE *InputFile, char *ReadBuffer);
int T_fgets(FILE *InputFile, char *ReadBuffer);
int T_fgetc(FILE *InputFile, char *ReadBuffer);
int T_fread(FILE *InputFile);
/* Output functions */
void PrintHeader(char *CommandLineArgs[], long FileLength);
void PrintLine(
char *TextReadFromFile,
long CurrentLineNumber,
long LengthOfLine,
long OffsetOfStartOfCurrentLine,
long *OffsetOfEndOfPreviousLine,
int OffsetError
);
/* Utility functions */
void HR(int LengthOfHorizontalRule);
void syntax(void);
/******************************************************************************/
int main(int argc, char *argv[])
/******************************************************************************/
{
/* Array of pointers to read functions */
int (*GetLine[3])(FILE*, char*) = { T_fscanf, T_fgets, T_fgetc };
int iReadMode; /* Index into *GetLine[] array */
int iReadReturn; /* Result of read function */
int isFilePosErr; /* Boolean indicating file offset error */
long lFileLen; /* Length of file */
long lLastFilePos; /* Byte offset of end of previous line */
long lLineCount; /* Line count accumulator */
long lLineLen; /* Length of current line */
long lThisFilePos; /* Byte offset of start of current line */
char szReadLine[MAX_REC_LEN]; /* Input buffer */
FILE *inputFilePtr; /* Pointer to input file */
if (argc < 4) /* All arguments are required */
{
syntax();
return 1;
}
/* Set index into function pointer array based on command line */
if (strcmp(argv[3], "fscanf") == 0)
iReadMode = 0;
else if (strcmp(argv[3], "fgets") == 0)
iReadMode = 1;
else if (strcmp(argv[3], "fgetc") == 0)
iReadMode = 2;
else if (strcmp(argv[3], "fread") == 0)
iReadMode = 3;
else /* Oops */
{
syntax();
return 1;
}
if (strcmp(argv[2], "t") == 0)
inputFilePtr = fopen(argv[1], "r"); /* Open in TEXT mode */
else if (strcmp(argv[2], "b") == 0)
inputFilePtr = fopen(argv[1], "rb"); /* Open in BINARY mode */
else /* Oops */
{
syntax();
return 1;
}
if (inputFilePtr == NULL ) /* Could not open file */
{
printf("Error opening %s: %s (%u)\n", argv[1], strerror(errno), errno);
return 1;
}
fseek(inputFilePtr, 0L, SEEK_END); /* Position to end of file */
lFileLen = ftell(inputFilePtr); /* Get file length */
rewind(inputFilePtr); /* Back to start of file */
PrintHeader(argv, lFileLen); /* Print the header info */
/*
* The implementation of the fread() function in this program is
* different enough from the other read methods that it's easiest
* to just call it explicitly and quit.
*/
if (iReadMode == 3) /* Use fread() */
{
iReadReturn = T_fread(inputFilePtr); /* Read the file and print output */
fclose(inputFilePtr); /* Close it */
HR(80); /* Print a separator line */
return (iReadReturn ? 0 : 1); /* Exit with success or error code */
}
/* At this point, we'll be using fscanf(), fgets(), or fgetc() */
lLineCount = 0L; /* No lines read yet */
lLastFilePos = -1L; /* So first line doesn't show an offset error */
while (1)
{
isFilePosErr = 0; /* Clear error flag */
lThisFilePos = ftell(inputFilePtr); /* Offset of start of line */
/* This will not necessarily be */
/* the absolute file offset if */
/* the file is opened in TEXT */
/* mode. */
if (lThisFilePos != lLastFilePos + 1) /* Set error flag if not next byte */
isFilePosErr = 1;
szReadLine[0] = '\0'; /* Clear buffer for next line */
/* Read the next line with the appropriate read function */
iReadReturn = (*GetLine[iReadMode])(inputFilePtr, szReadLine);
if (iReadReturn < 0) /* Error reading line */
{
/*
* Any system error code generated in the read functions is returned
* as a negative number so we can use positive numbers to indicate
* success. Therefore, we need to 're-negative' it to convert it back
* to the original error code.
*
* Error codes are implentation-dependent, but as far as I know, they
* are always positive integers.
*/
printf("Error reading %s: %s (%u)\n",
argv[1], strerror(-errno), -errno);
break;
}
lLineLen = strlen(szReadLine); /* Get length of line */
if (lLineLen) /* Got some data */
{
++lLineCount; /* Increment line counter */
/* Print the line's detail */
PrintLine(szReadLine, lLineCount, lLineLen,
lThisFilePos, &lLastFilePos, isFilePosErr);
}
if (iReadReturn == 0) /* End of file reached */
{
lThisFilePos = ftell(inputFilePtr); /* EOF offset */
HR(80); /* Print a separator line */
printf("EOF at offset %#x (dec %ld)\n", (int)lThisFilePos, lThisFilePos);
break;
}
}/* end while (1) */
fclose(inputFilePtr); /* Close the file */
HR(80); /* Print a separator line */
return 0; /* Exit with success code */
} /* end main() */
/******************************************************************************/
int T_fscanf(FILE *input, char *output) /* Use: Read text file w/fscanf */
/* */
/* Arguments: FILE *input */
/* Pointer to input file */
/* char *output */
/* Read buffer */
/* */
/* Return: int */
/* 0 = end of file */
/* >0 = # of fields read */
/******************************************************************************/
{
/*
* The fscanf() function has some limitations that usually make it
* inappropriate for reading text files, the main one being that
* it will stop reading at the first space character. It is included
* here for completeness.
*/
int iReturn = fscanf(input, "%s", output); /* Read from file */
if (iReturn == EOF) /* End of file reached */
return 0;
return iReturn;
} /* end T_fscanf() */
/******************************************************************************/
int T_fgets(FILE *input, char *output) /* Use: Read next line of text */
/* file with fgets */
/* */
/* Arguments: FILE *input */
/* Pointer to input file */
/* char *output */
/* Read buffer */
/* */
/* Return: int */
/* <0 = error */
/* 0 = end of file */
/* 1 = line read okay */
/******************************************************************************/
{
/*
* The fgets() function will read up to 'MAX_REC_LEN' characters
* (1K in this program), but will stop at the first newline
* (which is a LF in the three compilers tested).
*
* If the line length is greater than 'MAX_REC_LEN', we won't get
* the entire line. A real application should take this into account.
*/
fgets(output, MAX_REC_LEN, input); /* Read the line */
if (ferror(input)) /* Error reading */
return -errno; /* Convert code to negative number */
if (feof(input)) /* End of file reached */
return 0;
return 1;
} /* end T_fgets() */
/******************************************************************************/
int T_fgetc(FILE *input, char *output) /* Use: Read next line of text */
/* file with fgetc */
/* */
/* Arguments: FILE *input */
/* Pointer to input file */
/* char *output */
/* Read buffer */
/* */
/* Return: int */
/* <0 = error */
/* 0 = end of file */
/* 1 = line read okay */
/******************************************************************************/
{
/*
* This function repeatedly calls fgetc(), reading one character at
* a time, until it encounters the first character FOLLOWING a CR
* or LF that is NOT a CR or LF (or reaches the end of file). It
* assumes that everything up to (but NOT including) this character
* is part of the current line.
*
* As a result, this function will NOT read BLANK lines correctly.
* It will include ALL CRs and LFs as the trailing characters
* on the current line. A real application should take this into
* account.
*
* This function works okay, but reading a file one byte at a time
* is rather inefficient. See the T_fread() function in this program
* for a better approach.
*/
int iReturn = 1; /* Return value (Innocent until proved guilty) */
int iThisChar; /* Current character */
int isNewline = 0; /* Boolean indicating we've read a CR or LF */
long lIndex = 0L; /* Index into read buffer */
while (1) /* Will exit on error, end of line, or end of file */
{
iThisChar = fgetc(input); /* Read the next character */
if (ferror(input)) /* Error reading */
{
iReturn = -errno; /* Convert to negative number */
break;
}
if (iThisChar == EOF) /* End of file reached */
{
/*
* If we've already read characters on this line put the EOF back
* into the stream (ungetc()). We'll end on the NEXT call to this
* function.
*/
if (lIndex > 0)
ungetc(iThisChar, input);
else /* Nothing read but EOF; we're done with the file */
iReturn = 0;
break;
}
if (!isNewline) /* Haven't read a CR or LF yet */
{
if (iThisChar == CR || iThisChar == LF) /* This char IS a CR or LF */
isNewline = 1; /* Set flag */
}
else /* We've already read one or more CRs or LFs */
{
if (iThisChar != CR && iThisChar != LF) /* This char is NOT a CR or LF */
{
ungetc(iThisChar, input); /* Put char back in stream */
break; /* Done reading this line */
}
}
output[lIndex++] = iThisChar; /* Put char in read buffer */
} /* end while (1) */
output[lIndex] = '\0'; /* Terminate the read buffer */
return iReturn;
} /* end T_fgetc() */
/******************************************************************************/
int T_fread(FILE *input) /* Use: Read text file using fread() */
/* */
/* Arguments: FILE *input */
/* Pointer to input file */
/* */
/* Return: int */
/* 0 = error */
/* 1 = success */
/******************************************************************************/
{
/*
* This function reads the ENTIRE FILE into a character array and
* then parses the array to determine the contents of each line.
* This is lightning-fast, but may not work for large files. (See the
* notes preceding the call to calloc() in this function.)
*
* This routine combines the functionality of the main() and T_fgetc()
* functions in this program (although, unlike T_fgetc(), it parses
* the lines from memory rather than directly from disk). I wrote it
* this way so I could keep everything in one source file and easily
* share the output routines.
*
* As in the T_fgetc() function, this function will "collapse" any
* blank lines. This may not be appropriate in a real application.
*/
int isNewline; /* Boolean indicating we've read a CR or LF */
long lFileLen; /* Length of file */
long lIndex; /* Index into cThisLine array */
long lLineCount; /* Current line number */
long lLineLen; /* Current line length */
long lStartPos; /* Offset of start of current line */
long lTotalChars; /* Total characters read */
char cThisLine[MAX_REC_LEN]; /* Contents of current line */
char *cFile; /* Dynamically allocated buffer (entire file) */
char *cThisPtr; /* Pointer to current position in cFile */
fseek(input, 0L, SEEK_END); /* Position to end of file */
lFileLen = ftell(input); /* Get file length */
rewind(input); /* Back to start of file */
/*
* The next line attempts to reserve enough memory to read the
* entire file into memory (plus 1 byte for the null-terminator).
*
* The program will simply quit if the memory isn't available.
* This normally won't happen on computers that use virtual
* memory (such as Windows PCs), but a real application should
* make provisions for reading the file in smaller blocks.
*
* We could use malloc() to allocate the memory, but calloc()
* has the advantage of initializing all of the bits to 0, so
* we don't have to worry about adding the null-terminator
* (Essentially, every character initially IS a null-terminator).
*
* Note that we don't call the free() function to release the
* memory allocated by calloc(). It should not be necessary in
* this case because cFile is a local variable and will be
* deallocated automatically when this function ends.
*/
cFile = calloc(lFileLen + 1, sizeof(char));
if(cFile == NULL )
{
printf("\nInsufficient memory to read file.\n");
return 0;
}
fread(cFile, lFileLen, 1, input); /* Read the entire file into cFile */
lLineCount = 0L;
lTotalChars = 0L;
cThisPtr = cFile; /* Point to beginning of array */
while (*cThisPtr) /* Read until reaching null char */
{
lIndex = 0L; /* Reset counters and flags */
isNewline = 0;
lStartPos = lTotalChars;
while (*cThisPtr) /* Read until reaching null char */
{
if (!isNewline) /* Haven't read a CR or LF yet */
{
if (*cThisPtr == CR || *cThisPtr == LF) /* This char IS a CR or LF */
isNewline = 1; /* Set flag */
}
else if (*cThisPtr != CR && *cThisPtr != LF) /* Already found CR or LF */
break; /* Done with line */
cThisLine[lIndex++] = *cThisPtr++; /* Add char to output and increment */
++lTotalChars;
} /* end while (*cThisPtr) */
cThisLine[lIndex] = '\0'; /* Terminate the string */
++lLineCount; /* Increment the line counter */
lLineLen = strlen(cThisLine); /* Get length of line */
/* Print the detail for this line */
PrintLine(cThisLine, lLineCount, lLineLen, lStartPos, NULL, 0);
} /* end while (cThisPtr <= cEndPtr) */
HR(80); /* Print a separator line */
printf("Length of file array=%#x (dec %d)\n", strlen(cFile), strlen(cFile));
return 1;
} /* end T_fread() */
/******************************************************************************/
void PrintHeader(char *argv[], long lFileLen) /* Use: Print header info */
/* */
/* Arguments: char *argv[] */
/* Command line args*/
/* long lFileLen */
/* Length of file */
/* */
/* Return: void */
/******************************************************************************/
{
HR(80); /* Print a separator line */
/*
* lFileLen is cast to an (int) for display as a hex number because
* the Borland compiler couldn't handle converting a (long) to hex.
* Visual C++ and gcc were able to handle (long)s. The hex display
* will be screwed up if the file size is larger than the maximum
* signed (int).
*/
printf(
"File=%s, Size=%#x (dec %ld), Open mode=%s%s%s\n",
argv[1],
(int)lFileLen,
lFileLen,
(strcmp(argv[2], "t") == 0 ? "Text" : "Binary"),
(argv[3] == NULL ? "" : ", Read mode="),
(argv[3] == NULL ? "" : argv[3])
);
return;
} /* end PrintHeader() */
/******************************************************************************/
void PrintLine(char *szReadLine, long lLineCount, long lLineLen,
long lThisFilePos, long *lLastFilePos, int isFilePosErr)
/******************************************************************************/
/* Use: Print detail for current line */
/* */
/* Arguments: char *szReadLine = Read buffer containg text line */
/* long lLineCount = Current line number */
/* long lLineLen = Current line length */
/* long lThisFilePos = Offset of start of current line */
/* long *lLastFilePos = Offset of end of current line */
/* int isFilePosErr = True if start of current line is not */
/* 1 greater than end of last line */
/* */
/* Return: void */
/******************************************************************************/
{
char *cPtr; /* Pointer to current character */
HR(80); /* Print a separator line */
printf("LINE %ld, Length=%#x (dec %ld)\n",
lLineCount, (int)lLineLen, lLineLen); /* See PrintHeader() for an */
/* explanation of why the cast */
/* is needed. */
printf(" Offset:");
cPtr = szReadLine; /* Point to start of string */
if (isFilePosErr) /* Indicates offset error */
printf("*%2x", lThisFilePos++); /* Print '*' plus starting offset */
else /* Offset okay */
printf("%3x", lThisFilePos++); /* Just print starting offset */
for (++cPtr; cPtr < szReadLine + lLineLen; cPtr++) /* Remaining offsets */
printf("%3x", lThisFilePos++);
if (lLastFilePos != NULL) /* Set end position if arg passed */
*lLastFilePos = lThisFilePos - 1;
printf("\n Hex: ");
/* Print the hex values, including null terminator */
for (cPtr = szReadLine; cPtr <= szReadLine + lLineLen; cPtr++)
printf("%3x", *cPtr);
printf("\n Char: ");
/* Print the characters, including null terminator */
for (cPtr = szReadLine; cPtr <= szReadLine + lLineLen; cPtr++)
{
switch (*cPtr)
{
case 0: /* Null terminator */
printf(" \\0");
break;
case CR: /* Carriage return */
printf(" cr");
break;
case LF: /* Line feed */
printf(" lf");
break;
case EOF_MARKER: /* DOS end-of-file marker */
printf(" em");
break;
default: /* A 'real' character */
printf("%3c", *cPtr);
break;
} /* end switch (*cPtr) */
} /* end for (cPtr) */
printf("\n");
return;
} /* end PrintLine()
/******************************************************************************/
void HR(int iLen) /* Print a horizontal line of iLen length */
/******************************************************************************/
{
int i;
for (i = 0; i < iLen; i++)
printf("-");
printf("\n");
return;
} /* end HR() */
/******************************************************************************/
void syntax(void) /* Print correct command line syntax */
/******************************************************************************/
{
printf("\nSyntax: READ FileName OpenMode ReadMode\n\n");
printf(" OpenMode = \"t\" (text mode), or\n");
printf(" \"b\" (binary mode)\n\n");
printf(" ReadMode = \"fscanf\", or\n");
printf(" \"fgets\", or\n");
printf(" \"fgetc\", or\n");
printf(" \"fread\"\n");
return;
} /* end syntax() */
/* end read.c */
nanosani 20 Technize.net addict Team Colleague
It is the C code in java forum ????
tigerxx 0 Light Poster
hey please avoid the lazy procedural
always use oops
any way use BufferedReader br = BufferedReader (new InputStreamReader(new FileInputStream (new File("your file name"))))
and
use
String str=new String();
while((str=br.readLine())!=null){
System.out.println(str);
}
it will print the whole file
any more clarifications please write
}
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