Program which compares two files in different trees. Attributes and content.

master
Thomas Schmitt 15 years ago
parent c495ad3242
commit ecefdb4764
  1. 172
      test/compare_file.c

@ -0,0 +1,172 @@
/*
Compare two copies of a file object in as many aspects as i can imagine.
To compare tree /media/dvd and /original/dir :
find /media/dvd -exec compare_file '{}' /media/dvd /original/dir ';'
Copyright 2008 Thomas Schmitt, <scdbackup@gmx.net>
Provided under GPL version 2.
cc -g -o compare_file compare_file.c
*/
#include <ctype.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
/* @param flag bit0= compare atime
bit1= compare ctime
*/
int Compare_2_files(char *adr1, char *adr2, char *adrc,int flag)
{
struct stat s1, s2;
int ret, differs= 0, r1, r2, fd1, fd2, i;
char buf1[4096], buf2[4096];
off_t r1count= 0, r2count= 0, diffcount= 0, first_diff= -1;
ret= lstat(adr1, &s1);
if(ret==-1) {
printf("%s : cannot lstat() : %s\n", adr1, strerror(errno));
return(0);
}
ret= lstat(adr2, &s2);
if(ret==-1) {
printf("%s : cannot lstat() : %s\n", adr2, strerror(errno));
return(0);
}
/* Attributes */
if(s1.st_mode != s2.st_mode) {
printf("%s : st_mode : %7.7o <> %7.7o\n", adrc, s1.st_mode, s2.st_mode);
differs= 1;
}
if(s1.st_uid != s2.st_uid) {
printf("%s : st_uid : %d <> %d\n", adrc, s1.st_uid, s2.st_uid);
differs= 1;
}
if(s1.st_gid != s2.st_gid) {
printf("%s : st_gid : %d <> %d\n", adrc, s1.st_gid, s2.st_gid);
differs= 1;
}
if((S_ISCHR(s1.st_mode) && S_ISCHR(s2.st_mode)) ||
(S_ISBLK(s1.st_mode) && S_ISBLK(s2.st_mode))) {
if(s1.st_rdev != s2.st_rdev) {
printf("%s : %s st_rdev : %lu <> %lu\n", adrc,
(S_ISCHR(s1.st_mode) ? "S_IFCHR" : "S_IFBLK"),
(unsigned long) s1.st_rdev, (unsigned long) s1.st_rdev);
differs= 1;
}
}
if(S_ISREG(s2.st_mode) && s1.st_size!= s2.st_size) {
printf("%s : st_size : %.f <> %.f\n",
adrc, (double) s1.st_size, (double) s2.st_size);
differs= 1;
}
if(s1.st_mtime != s2.st_mtime) {
printf("%s : st_mtime : %u <> %u\n",
adrc, (unsigned int) s1.st_mtime, (unsigned int) s2.st_mtime);
differs= 1;
}
if(flag&1) {
if(s1.st_atime != s2.st_atime) {
printf("%s : st_atime : %u <> %u\n",
adrc, (unsigned int) s1.st_atime, (unsigned int) s2.st_atime);
differs= 1;
}
}
if(flag&2) {
if(s1.st_ctime != s2.st_ctime) {
printf("%s : st_ctime : %u <> %u\n",
adrc, (unsigned int) s1.st_ctime, (unsigned int) s2.st_ctime);
differs= 1;
}
}
if(S_ISREG(s1.st_mode)) {
fd1= open(adr1, O_RDONLY);
if(fd1==-1) {
printf("%s : cannot open() : %s\n", adr1, strerror(errno));
return(0);
}
fd2= open(adr1, O_RDONLY);
if(fd2==-1) {
printf("%s : cannot open() : %s\n", adr2, strerror(errno));
close(fd1);
return(0);
}
/* Content */
while(1) {
r1= read(fd1, buf1, sizeof(buf1));
r2= read(fd2, buf2, sizeof(buf2));
if((r1==EOF && r2==EOF) || (r1==0 && r2==0))
break;
if(r1==EOF || r1==0) {
printf("%s : early EOF after %d bytes\n", adr1, r1count);
differs= 1;
break;
}
r1count+= r1;
if(r2==EOF || r2<r1) {
printf("%s : early EOF after %d bytes\n", adr2, r2count);
differs= 1;
break;
}
if(r2>r1) {
printf("%s : early EOF after %d bytes\n", adr1, r1count);
differs= 1;
break;
}
r2count+= r2;
for(i= 0; i<r1; i++) {
if(buf1[i]!=buf2[i]) {
if(first_diff<0)
first_diff= i;
diffcount++;
}
}
}
if(diffcount>0) {
printf("%s : Content differs by %.f bytes. First at %.f\n",
adr1, (double) diffcount, (double) first_diff);
differs= 1;
}
}
close(fd1);
close(fd2);
return(!differs);
}
int main(int argc, char **argv)
{
int ret;
char adr1[4096], adr2[4096], adrc[4096];
if(argc<4) {
fprintf(stderr, "usage: %s path prefix1 prefix2\n", argv[0]);
exit(2);
}
if(strncmp(argv[1], argv[2], strlen(argv[2]))!=0) {
fprintf(stderr, "%s: path '%s' does not match prefix1 '%s'\n",
argv[0], argv[1], argv[2]);
exit(2);
}
strcpy(adr1, argv[1]);
strcpy(adrc, argv[1]+strlen(argv[2]));
sprintf(adr2, "%s%s%s", argv[3], (adrc[0]=='/' ? "" : "/"), adrc);
ret= Compare_2_files(adr1, adr2, adrc, 2);
exit(ret<=0);
}
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