/* 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