From: Ben Gras Date: Fri, 23 Dec 2005 16:36:00 +0000 (+0000) Subject: Ported bsd truncate(1) X-Git-Tag: v3.1.2a~466 X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/doxygen.log?a=commitdiff_plain;h=f6a3259ef871e4cdaac0e68c86a5bf7b9056efa7;p=minix.git Ported bsd truncate(1) --- diff --git a/commands/simple/Makefile b/commands/simple/Makefile index 65fbce5d7..d58d2b045 100755 --- a/commands/simple/Makefile +++ b/commands/simple/Makefile @@ -184,6 +184,7 @@ ALL = \ time \ touch \ tr \ + truncate \ treecmp \ tsort \ ttt \ @@ -794,6 +795,10 @@ treecmp: treecmp.c $(CCLD) -o $@ $? @install -S 4kw $@ +truncate: truncate.c + $(CCLD) -o $@ $? + @install -S 4kw $@ + ttt: ttt.c $(CCLD) -o $@ $? @install -S 4kw $@ @@ -1045,6 +1050,7 @@ install: \ /usr/bin/touch \ /usr/bin/tr \ /usr/bin/treecmp \ + /usr/bin/truncate \ /usr/bin/tsort \ /usr/bin/ttt \ /usr/bin/tty \ @@ -1568,6 +1574,9 @@ install: \ /usr/bin/treecmp: treecmp install -cs -o bin $? $@ +/usr/bin/truncate: truncate + install -cs -o bin $? $@ + /usr/bin/tsort: tsort install -cs -o bin $? $@ diff --git a/commands/simple/truncate.c b/commands/simple/truncate.c new file mode 100644 index 000000000..c4f30fcee --- /dev/null +++ b/commands/simple/truncate.c @@ -0,0 +1,208 @@ +/* + * Copyright (c) 2000 Sheldon Hearn . + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + +#include + +#include +#include +#include +#include +#include +#include + +static off_t parselength(char *, off_t *); +static void usage(void); + +static int no_create; +static int do_relative; +static int do_refer; +static int got_size; + +int +main(int argc, char **argv) +{ + struct stat sb; + mode_t omode; + off_t oflow, rsize, sz, tsize; + int ch, error, fd, oflags; + char *fname, *rname; + + rsize = tsize = 0; + error = 0; + rname = NULL; + while ((ch = getopt(argc, argv, "cr:s:")) != -1) + switch (ch) { + case 'c': + no_create = 1; + break; + case 'r': + do_refer = 1; + rname = optarg; + break; + case 's': + if (parselength(optarg, &sz) == -1) { + fprintf(stderr, + "invalid size argument `%s'", optarg); + exit(EXIT_FAILURE); + } + if (*optarg == '+' || *optarg == '-') + do_relative = 1; + got_size = 1; + break; + default: + usage(); + /* NOTREACHED */ + } + + argv += optind; + argc -= optind; + + /* + * Exactly one of do_refer or got_size must be specified. Since + * do_relative implies got_size, do_relative and do_refer are + * also mutually exclusive. See usage() for allowed invocations. + */ + if (do_refer + got_size != 1 || argc < 1) + usage(); + if (do_refer) { + if (stat(rname, &sb) == -1) { + fprintf(stderr, "%s", rname); + exit(EXIT_FAILURE); + } + tsize = sb.st_size; + } else if (do_relative) + rsize = sz; + else + tsize = sz; + + if (no_create) + oflags = O_WRONLY; + else + oflags = O_WRONLY | O_CREAT; + omode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH; + + while ((fname = *argv++) != NULL) { + if ((fd = open(fname, oflags, omode)) == -1) { + if (errno != ENOENT) { + perror(fname); + error++; + } + continue; + } + if (do_relative) { + if (fstat(fd, &sb) == -1) { + perror(fname); + error++; + continue; + } + oflow = sb.st_size + rsize; + if (oflow < (sb.st_size + rsize)) { + errno = EFBIG; + perror(fname); + error++; + continue; + } + tsize = oflow; + } + if (tsize < 0) + tsize = 0; + + if (ftruncate(fd, tsize) == -1) { + perror(fname); + error++; + continue; + } + + close(fd); + } + + return error ? EXIT_FAILURE : EXIT_SUCCESS; +} + +/* + * Return the numeric value of a string given in the form [+-][0-9]+[GMK] + * or -1 on format error or overflow. + */ +static off_t +parselength(char *ls, off_t *sz) +{ + off_t length, oflow; + int lsign; + + length = 0; + lsign = 1; + + switch (*ls) { + case '-': + lsign = -1; + case '+': + ls++; + } + +#define ASSIGN_CHK_OFLOW(x, y) if (x < y) return -1; y = x + /* + * Calculate the value of the decimal digit string, failing + * on overflow. + */ + while (isdigit(*ls)) { + oflow = length * 10 + *ls++ - '0'; + ASSIGN_CHK_OFLOW(oflow, length); + } + + switch (*ls) { + case 'G': + case 'g': + oflow = length * 1024; + ASSIGN_CHK_OFLOW(oflow, length); + case 'M': + case 'm': + oflow = length * 1024; + ASSIGN_CHK_OFLOW(oflow, length); + case 'K': + case 'k': + if (ls[1] != '\0') + return -1; + oflow = length * 1024; + ASSIGN_CHK_OFLOW(oflow, length); + case '\0': + break; + default: + return -1; + } + + *sz = length * lsign; + return 0; +} + +static void +usage(void) +{ + fprintf(stderr, "%s\n%s\n", + "usage: truncate [-c] -s [+|-]size[K|k|M|m|G|g] file ...", + " truncate [-c] -r rfile file ..."); + exit(EXIT_FAILURE); +}