| /* 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; |
| } |