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Matt Bishop Office: 2209 Watershed Sciences Phone: +1 (530) 752-8060 Email: mabishop@ucdavis.edu |
Version of April 2, 2024 at 12:13PM
/*
* PRINTLINE1 -- Read a file name and print it on the standard output
* each line prefixed by the line number
* this version uses fgets and fputs (last prints line directly)
*
* Usage: printfile1
*
* Inputs: file names; EOF to exit
* Output: contents of file, each line prefixed by line number
* Exit Code: number of files it could not open
*
* Matt Bishop, ECS 36A, Fall 2019
*
* Oct. 22, 2015 -- original program written
* Oct. 23, 2019 -- modified for ECS 36A
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*
* useful macros
*/
#define MAXFILENAMESIZE 1024 /* maximum length of file name */
#define MAXLINELENGTH 1000 /* maximum line length */
/*
* COPYOUT -- copy the contents of a file to standard output using fgets
*
* parameters: FILE *fp pointer to file to be copied out
* return: none
* assumptions: fp points to a file
* side effects: prints the line number followed by tab followed by line
*/
void copyout(FILE *fp)
{
char buf[MAXLINELENGTH]; /* buffer to hold line */
static int lineno = 1; /* current line number */
/*
* read until done
*/
while(fgets(buf, MAXLINELENGTH, fp) != NULL){
/* not done yet so print line number, then line */
printf("%6d\t", lineno++);
fputs(buf, stdout);
}
}
/*
* read a file name from the standard input,
* open it, and print it with line numbers
* before each line
*/
int main(void)
{
char fname[MAXFILENAMESIZE]; /* the file name(s) */
FILE *fp; /* file pointer */
int rv = 0; /* number of files that couldn't be opened */
/*
* read one file name per line, and do the dirty deeds
* then get the next one, -, until EOF
*/
while(printf("file name> "),
fgets(fname, MAXFILENAMESIZE, stdin) != NULL){
/* clobber trailing newline */
if (fname[strlen(fname)-1] == '\n')
fname[strlen(fname)-1] ='\0';
/* open the file */
if ((fp = fopen(fname, "r")) == NULL){
fprintf(stderr, "Could not open file %s\n", fname);
rv++;
continue;
}
/* copy the file, putting line numbers in front of each line */
copyout(fp);
/* now close it */
(void) fclose(fp);
}
putchar('\n');
/*
* say goodbye!
*/
exit(rv);
}
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ECS 36A, Programming & Problem Solving Version of April 2, 2024 at 12:13PM
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You can get the raw source code here.
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