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- /* vi: set sw=4 ts=4: */
- /*
- * Utility routines.
- *
- * Copyright (C) 2005, 2006 Rob Landley <rob@landley.net>
- * Copyright (C) 2004 Erik Andersen <andersen@codepoet.org>
- * Copyright (C) 2001 Matt Krai
- *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
- */
- /* for getline() [GNUism]
- #ifndef _GNU_SOURCE
- #define _GNU_SOURCE 1
- #endif
- */
- #include "libbb.h"
- /* This function reads an entire line from a text file, up to a newline
- * or NUL byte, inclusive. It returns a malloc'ed char * which
- * must be free'ed by the caller. If end is NULL '\n' isn't considered
- * end of line. If end isn't NULL, length of the chunk is stored in it.
- * If lineno is not NULL, *lineno is incremented for each line,
- * and also trailing '\' is recognized as line continuation.
- *
- * Returns NULL if EOF/error. */
- char* FAST_FUNC bb_get_chunk_with_continuation(FILE *file, int *end, int *lineno)
- {
- int ch;
- int idx = 0;
- char *linebuf = NULL;
- int linebufsz = 0;
- while ((ch = getc(file)) != EOF) {
- /* grow the line buffer as necessary */
- if (idx >= linebufsz) {
- linebufsz += 256;
- linebuf = xrealloc(linebuf, linebufsz);
- }
- linebuf[idx++] = (char) ch;
- if (!ch)
- break;
- if (end && ch == '\n') {
- if (lineno == NULL)
- break;
- (*lineno)++;
- if (idx < 2 || linebuf[idx-2] != '\\')
- break;
- idx -= 2;
- }
- }
- if (end)
- *end = idx;
- if (linebuf) {
- // huh, does fgets discard prior data on error like this?
- // I don't think so....
- //if (ferror(file)) {
- // free(linebuf);
- // return NULL;
- //}
- linebuf = xrealloc(linebuf, idx + 1);
- linebuf[idx] = '\0';
- }
- return linebuf;
- }
- char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end)
- {
- return bb_get_chunk_with_continuation(file, end, NULL);
- }
- /* Get line, including trailing \n if any */
- char* FAST_FUNC xmalloc_fgets(FILE *file)
- {
- int i;
- return bb_get_chunk_from_file(file, &i);
- }
- /* Get line. Remove trailing \n */
- char* FAST_FUNC xmalloc_fgetline(FILE *file)
- {
- int i;
- char *c = bb_get_chunk_from_file(file, &i);
- if (i && c[--i] == '\n')
- c[i] = '\0';
- return c;
- }
- #if 0
- /* GNUism getline() should be faster (not tested) than a loop with fgetc */
- /* Get line, including trailing \n if any */
- char* FAST_FUNC xmalloc_fgets(FILE *file)
- {
- char *res_buf = NULL;
- size_t res_sz;
- if (getline(&res_buf, &res_sz, file) == -1) {
- free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
- res_buf = NULL;
- }
- //TODO: trimming to res_sz?
- return res_buf;
- }
- /* Get line. Remove trailing \n */
- char* FAST_FUNC xmalloc_fgetline(FILE *file)
- {
- char *res_buf = NULL;
- size_t res_sz;
- res_sz = getline(&res_buf, &res_sz, file);
- if ((ssize_t)res_sz != -1) {
- if (res_buf[res_sz - 1] == '\n')
- res_buf[--res_sz] = '\0';
- //TODO: trimming to res_sz?
- } else {
- free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
- res_buf = NULL;
- }
- return res_buf;
- }
- #endif
- #if 0
- /* Faster routines (~twice as fast). +170 bytes. Unused as of 2008-07.
- *
- * NB: they stop at NUL byte too.
- * Performance is important here. Think "grep 50gigabyte_file"...
- * Ironically, grep can't use it because of NUL issue.
- * We sorely need C lib to provide fgets which reports size!
- *
- * Update:
- * Actually, uclibc and glibc have it. man getline. It's GNUism,
- * but very useful one (if it's as fast as this code).
- * TODO:
- * - currently, sed and sort use bb_get_chunk_from_file and heavily
- * depend on its "stop on \n or \0" behavior, and STILL they fail
- * to handle all cases with embedded NULs correctly. So:
- * - audit sed and sort; convert them to getline FIRST.
- * - THEN ditch bb_get_chunk_from_file, replace it with getline.
- * - provide getline implementation for non-GNU systems.
- */
- static char* xmalloc_fgets_internal(FILE *file, int *sizep)
- {
- int len;
- int idx = 0;
- char *linebuf = NULL;
- while (1) {
- char *r;
- linebuf = xrealloc(linebuf, idx + 0x100);
- r = fgets(&linebuf[idx], 0x100, file);
- if (!r) {
- /* need to terminate in case this is error
- * (EOF puts NUL itself) */
- linebuf[idx] = '\0';
- break;
- }
- /* stupid. fgets knows the len, it should report it somehow */
- len = strlen(&linebuf[idx]);
- idx += len;
- if (len != 0xff || linebuf[idx - 1] == '\n')
- break;
- }
- *sizep = idx;
- if (idx) {
- /* xrealloc(linebuf, idx + 1) is up to caller */
- return linebuf;
- }
- free(linebuf);
- return NULL;
- }
- /* Get line, remove trailing \n */
- char* FAST_FUNC xmalloc_fgetline_fast(FILE *file)
- {
- int sz;
- char *r = xmalloc_fgets_internal(file, &sz);
- if (r && r[sz - 1] == '\n')
- r[--sz] = '\0';
- return r; /* not xrealloc(r, sz + 1)! */
- }
- char* FAST_FUNC xmalloc_fgets(FILE *file)
- {
- int sz;
- return xmalloc_fgets_internal(file, &sz);
- }
- /* Get line, remove trailing \n */
- char* FAST_FUNC xmalloc_fgetline(FILE *file)
- {
- int sz;
- char *r = xmalloc_fgets_internal(file, &sz);
- if (!r)
- return r;
- if (r[sz - 1] == '\n')
- r[--sz] = '\0';
- return xrealloc(r, sz + 1);
- }
- #endif
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