[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/app/busybox/src/editors/diff.c b/ap/app/busybox/src/editors/diff.c
new file mode 100644
index 0000000..b08ded3
--- /dev/null
+++ b/ap/app/busybox/src/editors/diff.c
@@ -0,0 +1,1025 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini diff implementation for busybox, adapted from OpenBSD diff.
+ *
+ * Copyright (C) 2010 by Matheus Izvekov <mizvekov@gmail.com>
+ * Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
+ * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+/*
+ * The following code uses an algorithm due to Harold Stone,
+ * which finds a pair of longest identical subsequences in
+ * the two files.
+ *
+ * The major goal is to generate the match vector J.
+ * J[i] is the index of the line in file1 corresponding
+ * to line i in file0. J[i] = 0 if there is no
+ * such line in file1.
+ *
+ * Lines are hashed so as to work in core. All potential
+ * matches are located by sorting the lines of each file
+ * on the hash (called "value"). In particular, this
+ * collects the equivalence classes in file1 together.
+ * Subroutine equiv replaces the value of each line in
+ * file0 by the index of the first element of its
+ * matching equivalence in (the reordered) file1.
+ * To save space equiv squeezes file1 into a single
+ * array member in which the equivalence classes
+ * are simply concatenated, except that their first
+ * members are flagged by changing sign.
+ *
+ * Next the indices that point into member are unsorted into
+ * array class according to the original order of file0.
+ *
+ * The cleverness lies in routine stone. This marches
+ * through the lines of file0, developing a vector klist
+ * of "k-candidates". At step i a k-candidate is a matched
+ * pair of lines x,y (x in file0, y in file1) such that
+ * there is a common subsequence of length k
+ * between the first i lines of file0 and the first y
+ * lines of file1, but there is no such subsequence for
+ * any smaller y. x is the earliest possible mate to y
+ * that occurs in such a subsequence.
+ *
+ * Whenever any of the members of the equivalence class of
+ * lines in file1 matable to a line in file0 has serial number
+ * less than the y of some k-candidate, that k-candidate
+ * with the smallest such y is replaced. The new
+ * k-candidate is chained (via pred) to the current
+ * k-1 candidate so that the actual subsequence can
+ * be recovered. When a member has serial number greater
+ * that the y of all k-candidates, the klist is extended.
+ * At the end, the longest subsequence is pulled out
+ * and placed in the array J by unravel
+ *
+ * With J in hand, the matches there recorded are
+ * checked against reality to assure that no spurious
+ * matches have crept in due to hashing. If they have,
+ * they are broken, and "jackpot" is recorded--a harmless
+ * matter except that a true match for a spuriously
+ * mated line may now be unnecessarily reported as a change.
+ *
+ * Much of the complexity of the program comes simply
+ * from trying to minimize core utilization and
+ * maximize the range of doable problems by dynamically
+ * allocating what is needed and reusing what is not.
+ * The core requirements for problems larger than somewhat
+ * are (in words) 2*length(file0) + length(file1) +
+ * 3*(number of k-candidates installed), typically about
+ * 6n words for files of length n.
+ */
+
+//usage:#define diff_trivial_usage
+//usage: "[-abBdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] FILE1 FILE2"
+//usage:#define diff_full_usage "\n\n"
+//usage: "Compare files line by line and output the differences between them.\n"
+//usage: "This implementation supports unified diffs only.\n"
+//usage: "\n -a Treat all files as text"
+//usage: "\n -b Ignore changes in the amount of whitespace"
+//usage: "\n -B Ignore changes whose lines are all blank"
+//usage: "\n -d Try hard to find a smaller set of changes"
+//usage: "\n -i Ignore case differences"
+//usage: "\n -L Use LABEL instead of the filename in the unified header"
+//usage: "\n -N Treat absent files as empty"
+//usage: "\n -q Output only whether files differ"
+//usage: "\n -r Recurse"
+//usage: "\n -S Start with FILE when comparing directories"
+//usage: "\n -T Make tabs line up by prefixing a tab when necessary"
+//usage: "\n -s Report when two files are the same"
+//usage: "\n -t Expand tabs to spaces in output"
+//usage: "\n -U Output LINES lines of context"
+//usage: "\n -w Ignore all whitespace"
+
+#include "libbb.h"
+
+#if 0
+# define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)
+#else
+# define dbg_error_msg(...) ((void)0)
+#endif
+
+enum { /* print_status() and diffreg() return values */
+ STATUS_SAME, /* files are the same */
+ STATUS_DIFFER, /* files differ */
+ STATUS_BINARY, /* binary files differ */
+};
+
+enum { /* Commandline flags */
+ FLAG_a,
+ FLAG_b,
+ FLAG_d,
+ FLAG_i,
+ FLAG_L, /* never used, handled by getopt32 */
+ FLAG_N,
+ FLAG_q,
+ FLAG_r,
+ FLAG_s,
+ FLAG_S, /* never used, handled by getopt32 */
+ FLAG_t,
+ FLAG_T,
+ FLAG_U, /* never used, handled by getopt32 */
+ FLAG_w,
+ FLAG_u, /* ignored, this is the default */
+ FLAG_p, /* not implemented */
+ FLAG_B,
+ FLAG_E, /* not implemented */
+};
+#define FLAG(x) (1 << FLAG_##x)
+
+/* We cache file position to avoid excessive seeking */
+typedef struct FILE_and_pos_t {
+ FILE *ft_fp;
+ off_t ft_pos;
+} FILE_and_pos_t;
+
+struct globals {
+ smallint exit_status;
+ int opt_U_context;
+ const char *other_dir;
+ char *label[2];
+ struct stat stb[2];
+};
+#define G (*ptr_to_globals)
+#define exit_status (G.exit_status )
+#define opt_U_context (G.opt_U_context )
+#define label (G.label )
+#define stb (G.stb )
+#define INIT_G() do { \
+ SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+ opt_U_context = 3; \
+} while (0)
+
+typedef int token_t;
+
+enum {
+ /* Public */
+ TOK_EMPTY = 1 << 9, /* Line fully processed, you can proceed to the next */
+ TOK_EOF = 1 << 10, /* File ended */
+ /* Private (Only to be used by read_token() */
+ TOK_EOL = 1 << 11, /* we saw EOL (sticky) */
+ TOK_SPACE = 1 << 12, /* used -b code, means we are skipping spaces */
+ SHIFT_EOF = (sizeof(token_t)*8 - 8) - 1,
+ CHAR_MASK = 0x1ff, /* 8th bit is used to distinguish EOF from 0xff */
+};
+
+/* Restores full EOF from one 8th bit: */
+//#define TOK2CHAR(t) (((t) << SHIFT_EOF) >> SHIFT_EOF)
+/* We don't really need the above, we only need to have EOF != any_real_char: */
+#define TOK2CHAR(t) ((t) & CHAR_MASK)
+
+static void seek_ft(FILE_and_pos_t *ft, off_t pos)
+{
+ if (ft->ft_pos != pos) {
+ ft->ft_pos = pos;
+ fseeko(ft->ft_fp, pos, SEEK_SET);
+ }
+}
+
+/* Reads tokens from given fp, handling -b and -w flags
+ * The user must reset tok every line start
+ */
+static int read_token(FILE_and_pos_t *ft, token_t tok)
+{
+ tok |= TOK_EMPTY;
+ while (!(tok & TOK_EOL)) {
+ bool is_space;
+ int t;
+
+ t = fgetc(ft->ft_fp);
+ if (t != EOF)
+ ft->ft_pos++;
+ is_space = (t == EOF || isspace(t));
+
+ /* If t == EOF (-1), set both TOK_EOF and TOK_EOL */
+ tok |= (t & (TOK_EOF + TOK_EOL));
+ /* Only EOL? */
+ if (t == '\n')
+ tok |= TOK_EOL;
+
+ if (option_mask32 & FLAG(i)) /* Handcoded tolower() */
+ t = (t >= 'A' && t <= 'Z') ? t - ('A' - 'a') : t;
+
+ if ((option_mask32 & FLAG(w)) && is_space)
+ continue;
+
+ /* Trim char value to low 9 bits */
+ t &= CHAR_MASK;
+
+ if (option_mask32 & FLAG(b)) {
+ /* Was prev char whitespace? */
+ if (tok & TOK_SPACE) { /* yes */
+ if (is_space) /* this one too, ignore it */
+ continue;
+ tok &= ~TOK_SPACE;
+ } else if (is_space) {
+ /* 1st whitespace char.
+ * Set TOK_SPACE and replace char by ' ' */
+ t = TOK_SPACE + ' ';
+ }
+ }
+ /* Clear EMPTY */
+ tok &= ~(TOK_EMPTY + CHAR_MASK);
+ /* Assign char value (low 9 bits) and maybe set TOK_SPACE */
+ tok |= t;
+ break;
+ }
+#if 0
+ bb_error_msg("fp:%p tok:%x '%c'%s%s%s%s", fp, tok, tok & 0xff
+ , tok & TOK_EOF ? " EOF" : ""
+ , tok & TOK_EOL ? " EOL" : ""
+ , tok & TOK_EMPTY ? " EMPTY" : ""
+ , tok & TOK_SPACE ? " SPACE" : ""
+ );
+#endif
+ return tok;
+}
+
+struct cand {
+ int x;
+ int y;
+ int pred;
+};
+
+static int search(const int *c, int k, int y, const struct cand *list)
+{
+ int i, j;
+
+ if (list[c[k]].y < y) /* quick look for typical case */
+ return k + 1;
+
+ for (i = 0, j = k + 1;;) {
+ const int l = (i + j) >> 1;
+ if (l > i) {
+ const int t = list[c[l]].y;
+ if (t > y)
+ j = l;
+ else if (t < y)
+ i = l;
+ else
+ return l;
+ } else
+ return l + 1;
+ }
+}
+
+static unsigned isqrt(unsigned n)
+{
+ unsigned x = 1;
+ while (1) {
+ const unsigned y = x;
+ x = ((n / x) + x) >> 1;
+ if (x <= (y + 1) && x >= (y - 1))
+ return x;
+ }
+}
+
+static void stone(const int *a, int n, const int *b, int *J, int pref)
+{
+ const unsigned isq = isqrt(n);
+ const unsigned bound =
+ (option_mask32 & FLAG(d)) ? UINT_MAX : MAX(256, isq);
+ int clen = 1;
+ int clistlen = 100;
+ int k = 0;
+ struct cand *clist = xzalloc(clistlen * sizeof(clist[0]));
+ struct cand cand;
+ struct cand *q;
+ int *klist = xzalloc((n + 2) * sizeof(klist[0]));
+ /*clist[0] = (struct cand){0}; - xzalloc did it */
+ /*klist[0] = 0; */
+
+ for (cand.x = 1; cand.x <= n; cand.x++) {
+ int j = a[cand.x], oldl = 0;
+ unsigned numtries = 0;
+ if (j == 0)
+ continue;
+ cand.y = -b[j];
+ cand.pred = klist[0];
+ do {
+ int l, tc;
+ if (cand.y <= clist[cand.pred].y)
+ continue;
+ l = search(klist, k, cand.y, clist);
+ if (l != oldl + 1)
+ cand.pred = klist[l - 1];
+ if (l <= k && clist[klist[l]].y <= cand.y)
+ continue;
+ if (clen == clistlen) {
+ clistlen = clistlen * 11 / 10;
+ clist = xrealloc(clist, clistlen * sizeof(clist[0]));
+ }
+ clist[clen] = cand;
+ tc = klist[l];
+ klist[l] = clen++;
+ if (l <= k) {
+ cand.pred = tc;
+ oldl = l;
+ numtries++;
+ } else {
+ k++;
+ break;
+ }
+ } while ((cand.y = b[++j]) > 0 && numtries < bound);
+ }
+ /* Unravel */
+ for (q = clist + klist[k]; q->y; q = clist + q->pred)
+ J[q->x + pref] = q->y + pref;
+ free(klist);
+ free(clist);
+}
+
+struct line {
+ /* 'serial' is not used in the begining, so we reuse it
+ * to store line offsets, thus reducing memory pressure
+ */
+ union {
+ unsigned serial;
+ off_t offset;
+ };
+ unsigned value;
+};
+
+static void equiv(struct line *a, int n, struct line *b, int m, int *c)
+{
+ int i = 1, j = 1;
+
+ while (i <= n && j <= m) {
+ if (a[i].value < b[j].value)
+ a[i++].value = 0;
+ else if (a[i].value == b[j].value)
+ a[i++].value = j;
+ else
+ j++;
+ }
+ while (i <= n)
+ a[i++].value = 0;
+ b[m + 1].value = 0;
+ j = 0;
+ while (++j <= m) {
+ c[j] = -b[j].serial;
+ while (b[j + 1].value == b[j].value) {
+ j++;
+ c[j] = b[j].serial;
+ }
+ }
+ c[j] = -1;
+}
+
+static void unsort(const struct line *f, int l, int *b)
+{
+ int i;
+ int *a = xmalloc((l + 1) * sizeof(a[0]));
+ for (i = 1; i <= l; i++)
+ a[f[i].serial] = f[i].value;
+ for (i = 1; i <= l; i++)
+ b[i] = a[i];
+ free(a);
+}
+
+static int line_compar(const void *a, const void *b)
+{
+#define l0 ((const struct line*)a)
+#define l1 ((const struct line*)b)
+ int r = l0->value - l1->value;
+ if (r)
+ return r;
+ return l0->serial - l1->serial;
+#undef l0
+#undef l1
+}
+
+static void fetch(FILE_and_pos_t *ft, const off_t *ix, int a, int b, int ch)
+{
+ int i, j, col;
+ for (i = a; i <= b; i++) {
+ seek_ft(ft, ix[i - 1]);
+ putchar(ch);
+ if (option_mask32 & FLAG(T))
+ putchar('\t');
+ for (j = 0, col = 0; j < ix[i] - ix[i - 1]; j++) {
+ int c = fgetc(ft->ft_fp);
+ if (c == EOF) {
+ printf("\n\\ No newline at end of file\n");
+ return;
+ }
+ ft->ft_pos++;
+ if (c == '\t' && (option_mask32 & FLAG(t)))
+ do putchar(' '); while (++col & 7);
+ else {
+ putchar(c);
+ col++;
+ }
+ }
+ }
+}
+
+/* Creates the match vector J, where J[i] is the index
+ * of the line in the new file corresponding to the line i
+ * in the old file. Lines start at 1 instead of 0, that value
+ * being used instead to denote no corresponding line.
+ * This vector is dynamically allocated and must be freed by the caller.
+ *
+ * * fp is an input parameter, where fp[0] and fp[1] are the open
+ * old file and new file respectively.
+ * * nlen is an output variable, where nlen[0] and nlen[1]
+ * gets the number of lines in the old and new file respectively.
+ * * ix is an output variable, where ix[0] and ix[1] gets
+ * assigned dynamically allocated vectors of the offsets of the lines
+ * of the old and new file respectively. These must be freed by the caller.
+ */
+static NOINLINE int *create_J(FILE_and_pos_t ft[2], int nlen[2], off_t *ix[2])
+{
+ int *J, slen[2], *class, *member;
+ struct line *nfile[2], *sfile[2];
+ int pref = 0, suff = 0, i, j, delta;
+
+ /* Lines of both files are hashed, and in the process
+ * their offsets are stored in the array ix[fileno]
+ * where fileno == 0 points to the old file, and
+ * fileno == 1 points to the new one.
+ */
+ for (i = 0; i < 2; i++) {
+ unsigned hash;
+ token_t tok;
+ size_t sz = 100;
+ nfile[i] = xmalloc((sz + 3) * sizeof(nfile[i][0]));
+ /* ft gets here without the correct position, cant use seek_ft */
+ ft[i].ft_pos = 0;
+ fseeko(ft[i].ft_fp, 0, SEEK_SET);
+
+ nlen[i] = 0;
+ /* We could zalloc nfile, but then zalloc starts showing in gprof at ~1% */
+ nfile[i][0].offset = 0;
+ goto start; /* saves code */
+ while (1) {
+ tok = read_token(&ft[i], tok);
+ if (!(tok & TOK_EMPTY)) {
+ /* Hash algorithm taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578. */
+ /*hash = hash * 128 - hash + TOK2CHAR(tok);
+ * gcc insists on optimizing above to "hash * 127 + ...", thus... */
+ unsigned o = hash - TOK2CHAR(tok);
+ hash = hash * 128 - o; /* we want SPEED here */
+ continue;
+ }
+ if (nlen[i]++ == sz) {
+ sz = sz * 3 / 2;
+ nfile[i] = xrealloc(nfile[i], (sz + 3) * sizeof(nfile[i][0]));
+ }
+ /* line_compar needs hashes fit into positive int */
+ nfile[i][nlen[i]].value = hash & INT_MAX;
+ /* like ftello(ft[i].ft_fp) but faster (avoids lseek syscall) */
+ nfile[i][nlen[i]].offset = ft[i].ft_pos;
+ if (tok & TOK_EOF) {
+ /* EOF counts as a token, so we have to adjust it here */
+ nfile[i][nlen[i]].offset++;
+ break;
+ }
+start:
+ hash = tok = 0;
+ }
+ /* Exclude lone EOF line from the end of the file, to make fetch()'s job easier */
+ if (nfile[i][nlen[i]].offset - nfile[i][nlen[i] - 1].offset == 1)
+ nlen[i]--;
+ /* Now we copy the line offsets into ix */
+ ix[i] = xmalloc((nlen[i] + 2) * sizeof(ix[i][0]));
+ for (j = 0; j < nlen[i] + 1; j++)
+ ix[i][j] = nfile[i][j].offset;
+ }
+
+ /* length of prefix and suffix is calculated */
+ for (; pref < nlen[0] && pref < nlen[1] &&
+ nfile[0][pref + 1].value == nfile[1][pref + 1].value;
+ pref++);
+ for (; suff < nlen[0] - pref && suff < nlen[1] - pref &&
+ nfile[0][nlen[0] - suff].value == nfile[1][nlen[1] - suff].value;
+ suff++);
+ /* Arrays are pruned by the suffix and prefix length,
+ * the result being sorted and stored in sfile[fileno],
+ * and their sizes are stored in slen[fileno]
+ */
+ for (j = 0; j < 2; j++) {
+ sfile[j] = nfile[j] + pref;
+ slen[j] = nlen[j] - pref - suff;
+ for (i = 0; i <= slen[j]; i++)
+ sfile[j][i].serial = i;
+ qsort(sfile[j] + 1, slen[j], sizeof(*sfile[j]), line_compar);
+ }
+ /* nfile arrays are reused to reduce memory pressure
+ * The #if zeroed out section performs the same task as the
+ * one in the #else section.
+ * Peak memory usage is higher, but one array copy is avoided
+ * by not using unsort()
+ */
+#if 0
+ member = xmalloc((slen[1] + 2) * sizeof(member[0]));
+ equiv(sfile[0], slen[0], sfile[1], slen[1], member);
+ free(nfile[1]);
+
+ class = xmalloc((slen[0] + 1) * sizeof(class[0]));
+ for (i = 1; i <= slen[0]; i++) /* Unsorting */
+ class[sfile[0][i].serial] = sfile[0][i].value;
+ free(nfile[0]);
+#else
+ member = (int *)nfile[1];
+ equiv(sfile[0], slen[0], sfile[1], slen[1], member);
+ member = xrealloc(member, (slen[1] + 2) * sizeof(member[0]));
+
+ class = (int *)nfile[0];
+ unsort(sfile[0], slen[0], (int *)nfile[0]);
+ class = xrealloc(class, (slen[0] + 2) * sizeof(class[0]));
+#endif
+ J = xmalloc((nlen[0] + 2) * sizeof(J[0]));
+ /* The elements of J which fall inside the prefix and suffix regions
+ * are marked as unchanged, while the ones which fall outside
+ * are initialized with 0 (no matches), so that function stone can
+ * then assign them their right values
+ */
+ for (i = 0, delta = nlen[1] - nlen[0]; i <= nlen[0]; i++)
+ J[i] = i <= pref ? i :
+ i > (nlen[0] - suff) ? (i + delta) : 0;
+ /* Here the magic is performed */
+ stone(class, slen[0], member, J, pref);
+ J[nlen[0] + 1] = nlen[1] + 1;
+
+ free(class);
+ free(member);
+
+ /* Both files are rescanned, in an effort to find any lines
+ * which, due to limitations intrinsic to any hashing algorithm,
+ * are different but ended up confounded as the same
+ */
+ for (i = 1; i <= nlen[0]; i++) {
+ if (!J[i])
+ continue;
+
+ seek_ft(&ft[0], ix[0][i - 1]);
+ seek_ft(&ft[1], ix[1][J[i] - 1]);
+
+ for (j = J[i]; i <= nlen[0] && J[i] == j; i++, j++) {
+ token_t tok0 = 0, tok1 = 0;
+ do {
+ tok0 = read_token(&ft[0], tok0);
+ tok1 = read_token(&ft[1], tok1);
+
+ if (((tok0 ^ tok1) & TOK_EMPTY) != 0 /* one is empty (not both) */
+ || (!(tok0 & TOK_EMPTY) && TOK2CHAR(tok0) != TOK2CHAR(tok1))
+ ) {
+ J[i] = 0; /* Break the correspondence */
+ }
+ } while (!(tok0 & tok1 & TOK_EMPTY));
+ }
+ }
+
+ return J;
+}
+
+static bool diff(FILE* fp[2], char *file[2])
+{
+ int nlen[2];
+ off_t *ix[2];
+ FILE_and_pos_t ft[2];
+ typedef struct { int a, b; } vec_t[2];
+ vec_t *vec = NULL;
+ int i = 1, j, k, idx = -1;
+ bool anychange = false;
+ int *J;
+
+ ft[0].ft_fp = fp[0];
+ ft[1].ft_fp = fp[1];
+ /* note that ft[i].ft_pos is unintitalized, create_J()
+ * must not assume otherwise */
+ J = create_J(ft, nlen, ix);
+
+ do {
+ bool nonempty = false;
+
+ while (1) {
+ vec_t v;
+
+ for (v[0].a = i; v[0].a <= nlen[0] && J[v[0].a] == J[v[0].a - 1] + 1; v[0].a++)
+ continue;
+ v[1].a = J[v[0].a - 1] + 1;
+
+ for (v[0].b = v[0].a - 1; v[0].b < nlen[0] && !J[v[0].b + 1]; v[0].b++)
+ continue;
+ v[1].b = J[v[0].b + 1] - 1;
+ /*
+ * Indicate that there is a difference between lines a and b of the 'from' file
+ * to get to lines c to d of the 'to' file. If a is greater than b then there
+ * are no lines in the 'from' file involved and this means that there were
+ * lines appended (beginning at b). If c is greater than d then there are
+ * lines missing from the 'to' file.
+ */
+ if (v[0].a <= v[0].b || v[1].a <= v[1].b) {
+ /*
+ * If this change is more than 'context' lines from the
+ * previous change, dump the record and reset it.
+ */
+ int ct = (2 * opt_U_context) + 1;
+ if (idx >= 0
+ && v[0].a > vec[idx][0].b + ct
+ && v[1].a > vec[idx][1].b + ct
+ ) {
+ break;
+ }
+
+ for (j = 0; j < 2; j++)
+ for (k = v[j].a; k < v[j].b; k++)
+ nonempty |= (ix[j][k+1] - ix[j][k] != 1);
+
+ vec = xrealloc_vector(vec, 6, ++idx);
+ memcpy(vec[idx], v, sizeof(v));
+ }
+
+ i = v[0].b + 1;
+ if (i > nlen[0])
+ break;
+ J[v[0].b] = v[1].b;
+ }
+ if (idx < 0 || ((option_mask32 & FLAG(B)) && !nonempty))
+ goto cont;
+ if (!(option_mask32 & FLAG(q))) {
+ int lowa;
+ vec_t span, *cvp = vec;
+
+ if (!anychange) {
+ /* Print the context/unidiff header first time through */
+ printf("--- %s\n", label[0] ? label[0] : file[0]);
+ printf("+++ %s\n", label[1] ? label[1] : file[1]);
+ }
+
+ printf("@@");
+ for (j = 0; j < 2; j++) {
+ int a = span[j].a = MAX(1, (*cvp)[j].a - opt_U_context);
+ int b = span[j].b = MIN(nlen[j], vec[idx][j].b + opt_U_context);
+
+ printf(" %c%d", j ? '+' : '-', MIN(a, b));
+ if (a == b)
+ continue;
+ printf(",%d", (a < b) ? b - a + 1 : 0);
+ }
+ printf(" @@\n");
+ /*
+ * Output changes in "unified" diff format--the old and new lines
+ * are printed together.
+ */
+ for (lowa = span[0].a; ; lowa = (*cvp++)[0].b + 1) {
+ bool end = cvp > &vec[idx];
+ fetch(&ft[0], ix[0], lowa, end ? span[0].b : (*cvp)[0].a - 1, ' ');
+ if (end)
+ break;
+ for (j = 0; j < 2; j++)
+ fetch(&ft[j], ix[j], (*cvp)[j].a, (*cvp)[j].b, j ? '+' : '-');
+ }
+ }
+ anychange = true;
+ cont:
+ idx = -1;
+ } while (i <= nlen[0]);
+
+ free(vec);
+ free(ix[0]);
+ free(ix[1]);
+ free(J);
+ return anychange;
+}
+
+static int diffreg(char *file[2])
+{
+ FILE *fp[2];
+ bool binary = false, differ = false;
+ int status = STATUS_SAME, i;
+
+ fp[0] = stdin;
+ fp[1] = stdin;
+ for (i = 0; i < 2; i++) {
+ int fd = open_or_warn_stdin(file[i]);
+ if (fd == -1)
+ goto out;
+ /* Our diff implementation is using seek.
+ * When we meet non-seekable file, we must make a temp copy.
+ */
+ if (lseek(fd, 0, SEEK_SET) == -1 && errno == ESPIPE) {
+ char name[] = "/tmp/difXXXXXX";
+ int fd_tmp = xmkstemp(name);
+
+ unlink(name);
+ if (bb_copyfd_eof(fd, fd_tmp) < 0)
+ xfunc_die();
+ if (fd) /* Prevents closing of stdin */
+ close(fd);
+ fd = fd_tmp;
+ }
+ fp[i] = fdopen(fd, "r");
+ }
+
+ while (1) {
+ const size_t sz = COMMON_BUFSIZE / 2;
+ char *const buf0 = bb_common_bufsiz1;
+ char *const buf1 = buf0 + sz;
+ int j, k;
+ i = fread(buf0, 1, sz, fp[0]);
+ j = fread(buf1, 1, sz, fp[1]);
+ if (i != j) {
+ differ = true;
+ i = MIN(i, j);
+ }
+ if (i == 0)
+ break;
+ for (k = 0; k < i; k++) {
+ if (!buf0[k] || !buf1[k])
+ binary = true;
+ if (buf0[k] != buf1[k])
+ differ = true;
+ }
+ }
+ if (differ) {
+ if (binary && !(option_mask32 & FLAG(a)))
+ status = STATUS_BINARY;
+ else if (diff(fp, file))
+ status = STATUS_DIFFER;
+ }
+ if (status != STATUS_SAME)
+ exit_status |= 1;
+out:
+ fclose_if_not_stdin(fp[0]);
+ fclose_if_not_stdin(fp[1]);
+
+ return status;
+}
+
+static void print_status(int status, char *path[2])
+{
+ switch (status) {
+ case STATUS_BINARY:
+ case STATUS_DIFFER:
+ if ((option_mask32 & FLAG(q)) || status == STATUS_BINARY)
+ printf("Files %s and %s differ\n", path[0], path[1]);
+ break;
+ case STATUS_SAME:
+ if (option_mask32 & FLAG(s))
+ printf("Files %s and %s are identical\n", path[0], path[1]);
+ break;
+ }
+}
+
+#if ENABLE_FEATURE_DIFF_DIR
+struct dlist {
+ size_t len;
+ int s, e;
+ char **dl;
+};
+
+/* This function adds a filename to dl, the directory listing. */
+static int FAST_FUNC add_to_dirlist(const char *filename,
+ struct stat *sb UNUSED_PARAM,
+ void *userdata, int depth UNUSED_PARAM)
+{
+ struct dlist *const l = userdata;
+ const char *file = filename + l->len;
+ while (*file == '/')
+ file++;
+ l->dl = xrealloc_vector(l->dl, 6, l->e);
+ l->dl[l->e] = xstrdup(file);
+ l->e++;
+ return TRUE;
+}
+
+/* If recursion is not set, this function adds the directory
+ * to the list and prevents recursive_action from recursing into it.
+ */
+static int FAST_FUNC skip_dir(const char *filename,
+ struct stat *sb, void *userdata,
+ int depth)
+{
+ if (!(option_mask32 & FLAG(r)) && depth) {
+ add_to_dirlist(filename, sb, userdata, depth);
+ return SKIP;
+ }
+ if (!(option_mask32 & FLAG(N))) {
+ /* -r without -N: no need to recurse into dirs
+ * which do not exist on the "other side".
+ * Testcase: diff -r /tmp /
+ * (it would recurse deep into /proc without this code) */
+ struct dlist *const l = userdata;
+ filename += l->len;
+ if (filename[0]) {
+ struct stat osb;
+ char *othername = concat_path_file(G.other_dir, filename);
+ int r = stat(othername, &osb);
+ free(othername);
+ if (r != 0 || !S_ISDIR(osb.st_mode)) {
+ /* other dir doesn't have similarly named
+ * directory, don't recurse; return 1 upon
+ * exit, just like diffutils' diff */
+ exit_status |= 1;
+ return SKIP;
+ }
+ }
+ }
+ return TRUE;
+}
+
+static void diffdir(char *p[2], const char *s_start)
+{
+ struct dlist list[2];
+ int i;
+
+ memset(&list, 0, sizeof(list));
+ for (i = 0; i < 2; i++) {
+ /*list[i].s = list[i].e = 0; - memset did it */
+ /*list[i].dl = NULL; */
+
+ G.other_dir = p[1 - i];
+ /* We need to trim root directory prefix.
+ * Using list.len to specify its length,
+ * add_to_dirlist will remove it. */
+ list[i].len = strlen(p[i]);
+ recursive_action(p[i], ACTION_RECURSE | ACTION_FOLLOWLINKS,
+ add_to_dirlist, skip_dir, &list[i], 0);
+ /* Sort dl alphabetically.
+ * GNU diff does this ignoring any number of trailing dots.
+ * We don't, so for us dotted files almost always are
+ * first on the list.
+ */
+ qsort_string_vector(list[i].dl, list[i].e);
+ /* If -S was set, find the starting point. */
+ if (!s_start)
+ continue;
+ while (list[i].s < list[i].e && strcmp(list[i].dl[list[i].s], s_start) < 0)
+ list[i].s++;
+ }
+ /* Now that both dirlist1 and dirlist2 contain sorted directory
+ * listings, we can start to go through dirlist1. If both listings
+ * contain the same file, then do a normal diff. Otherwise, behaviour
+ * is determined by whether the -N flag is set. */
+ while (1) {
+ char *dp[2];
+ int pos;
+ int k;
+
+ dp[0] = list[0].s < list[0].e ? list[0].dl[list[0].s] : NULL;
+ dp[1] = list[1].s < list[1].e ? list[1].dl[list[1].s] : NULL;
+ if (!dp[0] && !dp[1])
+ break;
+ pos = !dp[0] ? 1 : (!dp[1] ? -1 : strcmp(dp[0], dp[1]));
+ k = pos > 0;
+ if (pos && !(option_mask32 & FLAG(N))) {
+ printf("Only in %s: %s\n", p[k], dp[k]);
+ exit_status |= 1;
+ } else {
+ char *fullpath[2], *path[2]; /* if -N */
+
+ for (i = 0; i < 2; i++) {
+ if (pos == 0 || i == k) {
+ path[i] = fullpath[i] = concat_path_file(p[i], dp[i]);
+ stat(fullpath[i], &stb[i]);
+ } else {
+ fullpath[i] = concat_path_file(p[i], dp[1 - i]);
+ path[i] = (char *)bb_dev_null;
+ }
+ }
+ if (pos)
+ stat(fullpath[k], &stb[1 - k]);
+
+ if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode))
+ printf("Common subdirectories: %s and %s\n", fullpath[0], fullpath[1]);
+ else if (!S_ISREG(stb[0].st_mode) && !S_ISDIR(stb[0].st_mode))
+ printf("File %s is not a regular file or directory and was skipped\n", fullpath[0]);
+ else if (!S_ISREG(stb[1].st_mode) && !S_ISDIR(stb[1].st_mode))
+ printf("File %s is not a regular file or directory and was skipped\n", fullpath[1]);
+ else if (S_ISDIR(stb[0].st_mode) != S_ISDIR(stb[1].st_mode)) {
+ if (S_ISDIR(stb[0].st_mode))
+ printf("File %s is a %s while file %s is a %s\n", fullpath[0], "directory", fullpath[1], "regular file");
+ else
+ printf("File %s is a %s while file %s is a %s\n", fullpath[0], "regular file", fullpath[1], "directory");
+ } else
+ print_status(diffreg(path), fullpath);
+
+ free(fullpath[0]);
+ free(fullpath[1]);
+ }
+ free(dp[k]);
+ list[k].s++;
+ if (pos == 0) {
+ free(dp[1 - k]);
+ list[1 - k].s++;
+ }
+ }
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(list[0].dl);
+ free(list[1].dl);
+ }
+}
+#endif
+
+#if ENABLE_FEATURE_DIFF_LONG_OPTIONS
+static const char diff_longopts[] ALIGN1 =
+ "ignore-case\0" No_argument "i"
+ "ignore-tab-expansion\0" No_argument "E"
+ "ignore-space-change\0" No_argument "b"
+ "ignore-all-space\0" No_argument "w"
+ "ignore-blank-lines\0" No_argument "B"
+ "text\0" No_argument "a"
+ "unified\0" Required_argument "U"
+ "label\0" Required_argument "L"
+ "show-c-function\0" No_argument "p"
+ "brief\0" No_argument "q"
+ "expand-tabs\0" No_argument "t"
+ "initial-tab\0" No_argument "T"
+ "recursive\0" No_argument "r"
+ "new-file\0" No_argument "N"
+ "report-identical-files\0" No_argument "s"
+ "starting-file\0" Required_argument "S"
+ "minimal\0" No_argument "d"
+ ;
+#endif
+
+int diff_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int diff_main(int argc UNUSED_PARAM, char **argv)
+{
+ int gotstdin = 0, i;
+ char *file[2], *s_start = NULL;
+ llist_t *L_arg = NULL;
+
+ INIT_G();
+
+ /* exactly 2 params; collect multiple -L <label>; -U N */
+ opt_complementary = "=2:L::U+";
+#if ENABLE_FEATURE_DIFF_LONG_OPTIONS
+ applet_long_options = diff_longopts;
+#endif
+ getopt32(argv, "abdiL:NqrsS:tTU:wupBE",
+ &L_arg, &s_start, &opt_U_context);
+ argv += optind;
+ while (L_arg)
+ label[!!label[0]] = llist_pop(&L_arg);
+ xfunc_error_retval = 2;
+ for (i = 0; i < 2; i++) {
+ file[i] = argv[i];
+ /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
+ if (LONE_DASH(file[i])) {
+ fstat(STDIN_FILENO, &stb[i]);
+ gotstdin++;
+ } else
+ xstat(file[i], &stb[i]);
+ }
+ xfunc_error_retval = 1;
+ if (gotstdin && (S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode)))
+ bb_error_msg_and_die("can't compare stdin to a directory");
+
+ /* Compare metadata to check if the files are the same physical file.
+ *
+ * Comment from diffutils source says:
+ * POSIX says that two files are identical if st_ino and st_dev are
+ * the same, but many file systems incorrectly assign the same (device,
+ * inode) pair to two distinct files, including:
+ * GNU/Linux NFS servers that export all local file systems as a
+ * single NFS file system, if a local device number (st_dev) exceeds
+ * 255, or if a local inode number (st_ino) exceeds 16777215.
+ */
+ if (ENABLE_DESKTOP
+ && stb[0].st_ino == stb[1].st_ino
+ && stb[0].st_dev == stb[1].st_dev
+ && stb[0].st_size == stb[1].st_size
+ && stb[0].st_mtime == stb[1].st_mtime
+ && stb[0].st_ctime == stb[1].st_ctime
+ && stb[0].st_mode == stb[1].st_mode
+ && stb[0].st_nlink == stb[1].st_nlink
+ && stb[0].st_uid == stb[1].st_uid
+ && stb[0].st_gid == stb[1].st_gid
+ ) {
+ /* files are physically the same; no need to compare them */
+ return STATUS_SAME;
+ }
+
+ if (S_ISDIR(stb[0].st_mode) && S_ISDIR(stb[1].st_mode)) {
+#if ENABLE_FEATURE_DIFF_DIR
+ diffdir(file, s_start);
+#else
+ bb_error_msg_and_die("no support for directory comparison");
+#endif
+ } else {
+ bool dirfile = S_ISDIR(stb[0].st_mode) || S_ISDIR(stb[1].st_mode);
+ bool dir = S_ISDIR(stb[1].st_mode);
+ if (dirfile) {
+ const char *slash = strrchr(file[!dir], '/');
+ file[dir] = concat_path_file(file[dir], slash ? slash + 1 : file[!dir]);
+ xstat(file[dir], &stb[dir]);
+ }
+ /* diffreg can get non-regular files here */
+ print_status(gotstdin > 1 ? STATUS_SAME : diffreg(file), file);
+
+ if (dirfile)
+ free(file[dir]);
+ }
+
+ return exit_status;
+}