blob: 34d33c79c9a12628a98031b1d0209cb5a4d4e7bd [file] [log] [blame]
/* vi: set sw=4 ts=4:
*
* patch.c - Apply a "universal" diff.
*
* Copyright 2007 Rob Landley <rob@landley.net>
*
* see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html
* (But only does -u, because who still cares about "ed"?)
*
* TODO:
* -b backup
* -l treat all whitespace as a single space
* -N ignore already applied
* -d chdir first
* -D define wrap #ifdef and #ifndef around changes
* -o outfile output here instead of in place
* -r rejectfile write rejected hunks to this file
*
* -E remove empty files --remove-empty-files
* -f force (no questions asked)
* -F fuzz (number, default 2)
* [file] which file to patch
USE_PATCH(NEWTOY(patch, "up#i:R", TOYFLAG_USR|TOYFLAG_BIN))
config PATCH
bool "patch"
default y
help
usage: patch [-i file] [-p depth] [-Ru]
Apply a unified diff to one or more files.
-i Input file (defaults=stdin)
-p number of '/' to strip from start of file paths (default=all)
-R Reverse patch.
-u Ignored (only handles "unified" diffs)
This version of patch only handles unified diffs, and only modifies
a file when all all hunks to that file apply. Patch prints failed
hunks to stderr, and exits with nonzero status if any hunks fail.
A file compared against /dev/null is created/deleted as appropriate.
*/
#include "toys.h"
DEFINE_GLOBALS(
char *infile;
long prefix;
struct double_list *plines, *flines;
long oldline, oldlen, newline, newlen, linenum;
int context, state, filein, fileout, filepatch;
char *tempname, *oldname;
)
#define TT this.patch
#define FLAG_REVERSE 1
#define FLAG_PATHLEN 4
static void do_line(void *data)
{
struct double_list *dlist = (struct double_list *)data;
if (TT.state && *dlist->data != TT.state)
fdprintf(TT.state == 2 ? 2: TT.fileout,
"%s\n", dlist->data+(TT.state>2 ? 1 : 0));
free(dlist->data);
}
static void dlist_add(struct double_list **list, char *data)
{
struct double_list *line = xmalloc(sizeof(struct double_list));
line->data = data;
if (*list) {
line->next = *list;
line->prev = (*list)->prev;
(*list)->prev->next = line;
(*list)->prev = line;
} else *list = line->next = line->prev = line;
}
static void finish_oldfile(void)
{
if (TT.tempname) replace_tempfile(TT.filein, TT.fileout, &TT.tempname);
}
static void fail_hunk(void)
{
if (!TT.plines) return;
TT.plines->prev->next = 0;
printf("Hunk FAILED.\n");
toys.exitval = 1;
// If we got to this point, we've seeked to the end. Discard changes to
// this file and advance to next file.
TT.state = 2;
llist_free(TT.plines, do_line);
TT.plines = NULL;
delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
TT.filein = -1;
}
static void apply_hunk(void)
{
struct double_list *plist, *buf = NULL;
int i = 0, backwards = 0, matcheof = 0,
reverse = toys.optflags & FLAG_REVERSE;
// Break doubly linked list so we can use singly linked traversal function.
TT.plines->prev->next = NULL;
// Match EOF if there aren't as many ending context lines as beginning
for (plist = TT.plines; plist; plist = plist->next) {
if (plist->data[0]==' ') i++;
else i = 0;
}
if (i < TT.context) matcheof++;
// Search for a place to apply this hunk. Match all context lines and
// lines to be removed.
plist = TT.plines;
buf = NULL;
i = 0;
// Start of for loop
if (TT.context) for (;;) {
char *data = get_line(TT.filein);
TT.linenum++;
// Skip lines we'd add.
while (plist && *plist->data == "+-"[reverse]) {
if (data && !backwards && !strcmp(data, plist->data+1)) {
backwards = 1;
fdprintf(2,"Possibly reversed hunk at %ld\n", TT.linenum);
}
plist = plist->next;
}
if (!data) {
// Matched EOF?
if (!plist && matcheof) break;
// File ended before we found a home for this hunk?
fail_hunk();
goto done;
}
dlist_add(&buf, data);
if (!plist || strcmp(data, plist->data+1)) { // Ignore whitespace?
// Match failed, hunk doesn't go here. Flush accumulated buffer
// so far.
buf->prev->next = NULL;
TT.state = 1;
llist_free(buf, do_line);
buf = NULL;
plist = TT.plines;
} else {
// Match, advance plist.
plist = plist->next;
if (!plist && !matcheof) break;
}
}
// Got it. Emit changed data.
TT.state = "-+"[reverse];
llist_free(TT.plines, do_line);
TT.plines = NULL;
done:
TT.state = 0;
if (buf) {
buf->prev->next = NULL;
llist_free(buf, do_line);
}
}
// state 0: Not in a hunk, look for +++.
// state 1: Found +++ file indicator, look for @@
// state 2: In hunk: counting initial context lines
// state 3: In hunk: getting body
void patch_main(void)
{
if (TT.infile) TT.filepatch = xopen(TT.infile, O_RDONLY);
TT.filein = TT.fileout = -1;
// Loop through the lines in the patch
for(;;) {
char *patchline;
patchline = get_line(TT.filepatch);
if (!patchline) break;
// Are we processing a hunk?
if (TT.state >= 2) {
if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
dlist_add(&TT.plines, patchline);
if (*patchline != '+') TT.oldlen--;
if (*patchline != '-') TT.newlen--;
// Context line?
if (*patchline==' ' && TT.state==2) TT.context++;
else TT.state=3;
if (!TT.oldlen && !TT.newlen) apply_hunk();
continue;
}
fail_hunk();
TT.state = 0;
continue;
}
// Open a new file?
if (!strncmp("--- ", patchline, 4)) {
char *s;
free(TT.oldname);
// Trim date from end of filename (if any). We don't care.
for (s = patchline+4; *s && *s!='\t'; s++)
if (*s=='\\' && s[1]) s++;
*s = 0;
TT.oldname = xstrdup(patchline+4);
} else if (!strncmp("+++ ", patchline, 4)) {
int i = 0, del = 0;
char *s, *start;
finish_oldfile();
// Trim date from end of filename (if any). We don't care.
for (s = patchline+4; *s && *s!='\t'; s++)
if (*s=='\\' && s[1]) s++;
*s = 0;
// If new file is /dev/null (before -p), we're deleting oldname
start = patchline+4;
if (!strcmp(start, "/dev/null")) {
start = TT.oldname;
del++;
} else start = patchline+4;
// handle -p path truncation.
for (s = start; *s;) {
if ((toys.optflags & FLAG_PATHLEN) && TT.prefix == i) break;
if (*(s++)=='/') {
start = s;
i++;
}
}
if (del) xunlink(TT.oldname);
// If we've got a file to open, do so.
else if (!(toys.optflags & FLAG_PATHLEN) || i <= TT.prefix) {
// If the old file was null, we're creating a new one.
if (!strcmp(TT.oldname, "/dev/null")) {
printf("creating %s\n", start);
s = strrchr(start, '/');
if (s) {
*s = 0;
xmkpath(start, -1);
*s = '/';
}
TT.filein = xcreate(start, O_CREAT|O_RDWR, 0666);
} else {
printf("patching %s\n", start);
TT.filein = xopen(start, O_RDWR);
}
TT.fileout = copy_tempfile(TT.filein, start, &TT.tempname);
TT.state = 1;
TT.context = 0;
TT.linenum = 0;
}
// Start a new hunk?
// Test filein rather than state to report only the first failed hunk.
} else if (TT.filein!=-1 && !strncmp("@@ -", patchline, 4) &&
4 == sscanf(patchline+4, "%ld,%ld +%ld,%ld", &TT.oldline,
&TT.oldlen, &TT.newline, &TT.newlen))
{
TT.context = 0;
TT.state = 2;
continue;
}
// If we didn't continue above, discard this line.
free(patchline);
}
finish_oldfile();
if (CFG_TOYBOX_FREE) {
close(TT.filepatch);
free(TT.oldname);
}
}