/* 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. */ //config:config DIFF //config: bool "diff" //config: default y //config: help //config: diff compares two files or directories and outputs the //config: differences between them in a form that can be given to //config: the patch command. //config: //config:config FEATURE_DIFF_LONG_OPTIONS //config: bool "Enable long options" //config: default y //config: depends on DIFF && LONG_OPTS //config: help //config: Enable use of long options. //config: //config:config FEATURE_DIFF_DIR //config: bool "Enable directory support" //config: default y //config: depends on DIFF //config: help //config: This option enables support for directory and subdirectory //config: comparison. //kbuild:lib-$(CONFIG_DIFF) += diff.o //applet:IF_DIFF(APPLET(diff, BB_DIR_USR_BIN, BB_SUID_DROP)) //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" #include "common_bufsiz.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 beginning, 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) { puts("\n\\ No newline at end of file"); 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] - ix[j][k - 1] != 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); } puts(" @@"); /* * 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 != STDIN_FILENO) close(fd); fd = fd_tmp; xlseek(fd, 0, SEEK_SET); } fp[i] = fdopen(fd, "r"); } setup_common_bufsiz(); 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"; #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; }