diff options
Diffstat (limited to 'coreutils/sum.c')
| -rw-r--r-- | coreutils/sum.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/coreutils/sum.c b/coreutils/sum.c new file mode 100644 index 000000000..93f4e22eb --- /dev/null +++ b/coreutils/sum.c @@ -0,0 +1,156 @@ +/* vi: set sw=4 ts=4: */ +/* + * sum -- checksum and count the blocks in a file + * Like BSD sum or SysV sum -r, except like SysV sum if -s option is given. + * + * Copyright (C) 86, 89, 91, 1995-2002, 2004 Free Software Foundation, Inc. + * Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org> + * Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org> + * + * Written by Kayvan Aghaiepour and David MacKenzie + * Taken from coreutils and turned into a busybox applet by Mike Frysinger + * + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + */ + +#include "busybox.h" + +/* 1 if any of the files read were the standard input */ +static int have_read_stdin; + +/* make a little more readable and avoid using strcmp for just 2 bytes */ +#define IS_STDIN(s) (s[0] == '-' && s[1] == '\0') + +/* Calculate and print the rotated checksum and the size in 1K blocks + of file FILE, or of the standard input if FILE is "-". + If PRINT_NAME is >1, print FILE next to the checksum and size. + The checksum varies depending on sizeof (int). + Return 1 if successful. */ +static int bsd_sum_file(const char *file, int print_name) +{ + FILE *fp; + int checksum = 0; /* The checksum mod 2^16. */ + uintmax_t total_bytes = 0; /* The number of bytes. */ + int ch; /* Each character read. */ + int ret = 0; + + if (IS_STDIN(file)) { + fp = stdin; + have_read_stdin++; + } else { + fp = fopen_or_warn(file, "r"); + if (fp == NULL) + goto out; + } + + while ((ch = getc(fp)) != EOF) { + ++total_bytes; + checksum = (checksum >> 1) + ((checksum & 1) << 15); + checksum += ch; + checksum &= 0xffff; /* Keep it within bounds. */ + } + + if (ferror(fp)) { + bb_perror_msg(file); + fclose_if_not_stdin(fp); + goto out; + } + + if (fclose_if_not_stdin(fp) == EOF) { + bb_perror_msg(file); + goto out; + } + ret++; + printf("%05d %5ju ", checksum, (total_bytes+1023)/1024); + if (print_name > 1) + puts(file); + else + puts(""); +out: + return ret; +} + +/* Calculate and print the checksum and the size in 512-byte blocks + of file FILE, or of the standard input if FILE is "-". + If PRINT_NAME is >0, print FILE next to the checksum and size. + Return 1 if successful. */ +#define MY_BUF_SIZE 8192 +static int sysv_sum_file(const char *file, int print_name) +{ + RESERVE_CONFIG_BUFFER(buf, MY_BUF_SIZE); + int fd; + uintmax_t total_bytes = 0; + + /* The sum of all the input bytes, modulo (UINT_MAX + 1). */ + unsigned int s = 0; + + if (IS_STDIN(file)) { + fd = 0; + have_read_stdin = 1; + } else { + fd = open(file, O_RDONLY); + if (fd == -1) + goto release_and_ret; + } + + while (1) { + size_t bytes_read = safe_read(fd, buf, MY_BUF_SIZE); + + if (bytes_read == 0) + break; + + if (bytes_read == -1) { +release_and_ret: + bb_perror_msg(file); + RELEASE_CONFIG_BUFFER(buf); + if (!IS_STDIN(file)) + close(fd); + return 0; + } + + total_bytes += bytes_read; + while (bytes_read--) + s += buf[bytes_read]; + } + + if (!IS_STDIN(file) && close(fd) == -1) + goto release_and_ret; + else + RELEASE_CONFIG_BUFFER(buf); + + { + int r = (s & 0xffff) + ((s & 0xffffffff) >> 16); + s = (r & 0xffff) + (r >> 16); + + printf("%d %ju ", s, (total_bytes+511)/512); + } + puts(print_name ? file : ""); + + return 1; +} + +int sum_main(int argc, char **argv) +{ + int flags; + int ok; + int (*sum_func)(const char *, int) = bsd_sum_file; + + /* give the bsd func priority over sysv func */ + flags = getopt32(argc, argv, "sr"); + if (flags & 1) + sum_func = sysv_sum_file; + if (flags & 2) + sum_func = bsd_sum_file; + + have_read_stdin = 0; + if ((argc - optind) == 0) + ok = sum_func("-", 0); + else + for (ok = 1; optind < argc; optind++) + ok &= sum_func(argv[optind], 1); + + if (have_read_stdin && fclose(stdin) == EOF) + bb_perror_msg_and_die("-"); + + exit(ok ? EXIT_SUCCESS : EXIT_FAILURE); +} |