allbery@uunet.UU.NET (Brandon S. Allbery - comp.sources.misc) (01/24/89)
Posting-number: Volume 6, Issue 10
Submitted-by: edf@ROCKY2.ROCKEFELLER.EDU (David MacKenzie)
Archive-name: ediff-v2
This is a new version of the diff-to-English translator I posted to this
group a few months ago. It contains a manual page, thanks to
R. P. C. Rodgers (rodgers@maxwell.mmwb.ucsf.edu), and a bugfix which
affects machines where sizeof (long) != sizeof (int), submitted by
Brian Renaud (uunet!umix!huron!bdr). I have also clarified the source
code somewhat. Other than those changes, it should work the same, but
since the program is short I decided that I might just as well repost it.
-----
David MacKenzie
Environmental Defense Fund
edf@rocky2.rockefeller.edu (...rutgers!cmcl2!rocky2!edf)
# This is a shell archive. Remove anything before this line,
# then unpack it by saving it in a file and typing "sh file".
#
# Wrapped by rocky2.rockefeller.edu!edf on Fri Dec 30 22:27:34 EST 1988
# Contents: ediff.1 ediff.c
echo x - ediff.1
sed 's/^@//' > "ediff.1" <<'@//E*O*F ediff.1//'
@.TH EDIFF 1L "30 December 1988"
@.SH NAME
ediff \- translate diff output into plain English
@.SH SYNOPSIS
@.B ediff
@.SH DESCRIPTION
@.I Ediff
is a filter which translates normal
@.IR diff (1)
output (not output produced with the
@.BR \-c ,
@.BR \-e ,
or
@.B \-f
@.I diff
options) into more readable English descriptions.
It copies non-diff material verbatim.
@.SH "SEE ALSO"
comm(1), diff(1), uniq(1)
@.SH AUTHOR
@.nf
David MacKenzie (edf@rocky2.rockefeller.edu).
Manual page written with the help of R. P. C. Rodgers
(rodgers@maxwell.mmwb.ucsf.edu).
@//E*O*F ediff.1//
chmod u=rw,g=r,o=r ediff.1
echo x - ediff.c
sed 's/^@//' > "ediff.c" <<'@//E*O*F ediff.c//'
/*
% cc -O ediff.c -o ediff && strip ediff
ediff - translate diff output into plain English
Translates only the normal diff output (not -c or -e/-f).
Use as a filter. Copies non-diff lines verbatim. Deletes NULs.
The Unix variant that runs on our Charles River Data Systems
machines, UNOS, comes with, in addition to the standard diff program,
a program called "difference" that produces more human-readable
output. Ediff provides the advantages of that program to users of other
versions of Unix (soon to include us, as we're hoping to get rid of
the CRDS machines before too long).
Thanks to Mike Haertel for the following information.
The exact meaning of the normal diff symbols is as follows
(all line numbers are the ORIGINAL line numbers in each file):
5,7c8,10
Change lines 5-7 of file 1 to read as lines 8-10 of file 2 (or, if changing
file 2 into file 1, change lines 8-10 of file 2 to read as lines 5-7
of file 1).
5,7d3
Delete lines 5-7 of file 1 (alternatively, append lines 5-7 of file 1
after line 3 of file 2).
8a12,15
Append lines 12-15 of file 2 after line 8 of file 1 (alternatively,
delete lines 12-15 of file 2).
David MacKenzie
edf@rocky2.rockefeller.edu
Latest revision: 12/30/88 */
#include <stdio.h>
/* Magic value meaning that a line number is missing from the input. */
#define UNUSED -1L
#ifdef __STDC__
#define P(x) x
#else
#define P(x) ()
#endif
void exit P((int));
void change P ((long, long, long, long));
void delete P ((long, long, long));
void append P ((long, long, long));
void copylines P ((long, int));
int readline P ((char *, int, FILE *));
char line[BUFSIZ]; /* Input line. */
main ()
{
long f1n1, f1n2, f2n1, f2n2; /* File 1, line number 1; etc. */
int result; /* Result of readline. */
for (;;)
{
result = readline (line, BUFSIZ, stdin);
f1n2 = f2n2 = UNUSED;
if
(sscanf (line, "%ld,%ldc%ld,%ld\n", &f1n1, &f1n2, &f2n1, &f2n2) == 4 ||
sscanf (line, "%ld,%ldc%ld\n", &f1n1, &f1n2, &f2n1) == 3 ||
sscanf (line, "%ldc%ld,%ld\n", &f1n1, &f2n1, &f2n2) == 3 ||
sscanf (line, "%ldc%ld\n", &f1n1, &f2n1) == 2)
change (f1n1, f1n2, f2n1, f2n2);
else if
(sscanf (line, "%ld,%ldd%ld\n", &f1n1, &f1n2, &f2n1) == 3 ||
sscanf (line, "%ldd%ld\n", &f1n1, &f2n1) == 2)
delete (f1n1, f1n2, f2n1);
else if
(sscanf (line, "%lda%ld,%ld\n", &f1n1, &f2n1, &f2n2) == 3 ||
sscanf (line, "%lda%ld\n", &f1n1, &f2n1) == 2)
append (f1n1, f2n1, f2n2);
else
{
/* The line wasn't the start of a diff. Copy it verbatim. */
fputs (line, stdout);
/* If it was a long line, copy the remainder. */
while (result == -1)
{
result = readline (line, BUFSIZ, stdin);
fputs (line, stdout);
}
}
}
}
void change (f1n1, f1n2, f2n1, f2n2)
long f1n1, f1n2, f2n1, f2n2;
{
printf ("\n-------- ");
if (f1n2 == UNUSED && f2n2 == UNUSED)
/* 1c1 */
printf ("1 line changed at %ld from:\n",
f1n1);
else if (f1n2 == UNUSED)
/* 1c1,2 */
printf ("1 line changed to %ld lines at %ld from:\n",
f2n2 - f2n1 + 1L, f1n1);
else if (f2n2 == UNUSED)
/* 1,2c1 */
printf ("%ld lines changed to 1 line at %ld-%ld from:\n",
f1n2 - f1n1 + 1L, f1n1, f1n2);
else if (f1n2 - f1n1 == f2n2 - f2n1)
/* 1,2c1,2 */
printf ("%ld lines changed at %ld-%ld from:\n",
f1n2 - f1n1 + 1L, f1n1, f1n2);
else
/* 1,2c1,3 */
printf ("%ld lines changed to %ld lines at %ld-%ld from:\n",
f1n2 - f1n1 + 1L, f2n2 - f2n1 + 1L, f1n1, f1n2);
if (f1n2 == UNUSED)
copylines (1L, 2); /* Skip the "< ". */
else
copylines (f1n2 - f1n1 + 1L, 2);
printf ("-------- to:\n");
(void) readline (line, BUFSIZ, stdin); /* Eat the "---" line. */
if (f2n2 == UNUSED)
copylines (1L, 2); /* Skip the "> ". */
else
copylines (f2n2 - f2n1 + 1L, 2);
}
/* ARGSUSED */
void delete (f1n1, f1n2, f2n1)
long f1n1, f1n2, f2n1;
{
printf ("\n-------- ");
if (f1n2 == UNUSED)
{
/* 1d1 */
printf ("1 line deleted at %ld:\n", f1n1);
copylines (1L, 2); /* Skip the "< ". */
}
else
{
/* 1,2d1 */
printf ("%ld lines deleted at %ld:\n", f1n2 - f1n1 + 1L, f1n1);
copylines (f1n2 - f1n1 + 1L, 2);
}
}
void append (f1n1, f2n1, f2n2)
long f1n1, f2n1, f2n2;
{
printf ("\n-------- ");
if (f2n2 == UNUSED)
{
/* 1a1 */
printf ("1 line added at %ld:\n", f1n1);
copylines (1L, 2); /* Skip the "> ". */
}
else
{
/* 1a1,2 */
printf ("%ld lines added at %ld:\n", f2n2 - f2n1 + 1L, f1n1);
copylines (f2n2 - f2n1 + 1L, 2);
}
}
/* Copy nlines lines from stdin to stdout; start writing at position skip. */
void copylines (nlines, skip)
long nlines;
int skip;
{
int result;
while (nlines-- > 0L)
{
result = readline (line, BUFSIZ, stdin);
fputs (&line[skip], stdout);
/* If it was a long line, copy the remainder. */
while (result == -1)
{
result = readline (line, BUFSIZ, stdin);
fputs (line, stdout);
}
}
}
/* Front end to fgets.
Exit if EOF; return 1 if end of line read, -1 if partial line read. */
int readline (s, length, fp)
char *s;
int length;
FILE *fp;
{
if (!fgets (s, length, fp))
exit (0);
if (s[strlen (s) - 1] == '\n')
return 1;
else
return -1;
}
@//E*O*F ediff.c//
chmod u=rw,g=r,o=r ediff.c
exit 0