1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
/*
* This is a simple template for a program that opens a file (or reads from
* stdin if no file is specified), then iterates over the lines of a file.
*/
void usage(char *prog) {
fprintf(stderr, "usage: %s [-v] <file>\n", prog);
exit(-1);
}
int main(int argc, char * argv[]) {
int opt,verbose=0,lines=0;
FILE *ifilef=stdin;
char *ifile=NULL,line[100];
while ( (opt = getopt(argc, argv, "v+")) != -1) {
switch (opt) {
case 'v': verbose++; break;
default: usage(argv[0]); break;
}
}
if (optind < argc) ifile=argv[optind++];
/* loop over the input */
if (ifile) {
if ( (ifilef = fopen(ifile,"r")) == NULL) {
fprintf(stderr,"can't open %s: %s\n", ifile, strerror(errno));
exit(-1);
}
}
while (fgets(line,sizeof(line),ifilef) != NULL) {
lines++;
if (verbose) fprintf(stderr, "read line: %s", line);
}
printf("%d lines read.\n",lines);
}
|
