Add io(1).
This commit is contained in:
Jonas 'Sortie' Termansen
parent
8bc1e6a2c0
commit
0344dbb3ee
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#include <sys/stat.h>
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#include <ctype.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <inttypes.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <strings.h>
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#include <unistd.h>
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static uintmax_t parse_amount(const char *string, blksize_t blksize)
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{
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const char *end;
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errno = 0;
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uintmax_t value = strtoumax(string, (char **)&end, 10);
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if (errno == ERANGE)
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errx(1, "argument overflow: %s", string);
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if (*end) {
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uintmax_t magnitude = 1;
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unsigned char magc = tolower((unsigned char)*end);
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switch (magc) {
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case 'k': magnitude = UINTMAX_C(1024) << 0; break;
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case 'm': magnitude = UINTMAX_C(1024) << 1; break;
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case 'g': magnitude = UINTMAX_C(1024) << 2; break;
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case 't': magnitude = UINTMAX_C(1024) << 3; break;
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case 'p': magnitude = UINTMAX_C(1024) << 4; break;
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case 'e': magnitude = UINTMAX_C(1024) << 5; break;
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case 'z': magnitude = UINTMAX_C(1024) << 6; break;
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case 'y': magnitude = UINTMAX_C(1024) << 7; break;
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case 'x': magnitude = blksize; break;
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default: errx(1, "unsupported unit: %s", end);
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}
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if (magc != 'x' || !(strcasecmp(end + 1, "B") == 0 ||
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strcasecmp(end + 1, "iB ")) )
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errx(1, "unsupported unit: %s", end);
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if (UINTMAX_MAX / magnitude < value)
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errx(1, "argument overflow: %s", string);
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value *= magnitude;
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}
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return value;
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}
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static size_t parse_size_t(const char *string, blksize_t blksize)
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{
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uintmax_t result = parse_amount(string, blksize);
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if (result != (size_t) result)
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errx(1, "argument overflow: %s", string);
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return result;
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}
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int main(int argc, char *argv[])
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{
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int input_fd = 0;
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int output_fd = 1;
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const char *input_path = NULL;
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const char *output_path = NULL;
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const char *block_size_str = NULL;
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off_t count = -1;
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const char *count_str = NULL;
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int opt;
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while ((opt = getopt(argc, argv, "b:c:i:I:o:O:q:s:S:v:")) != -1) {
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switch (opt) {
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case 'b': block_size_str = optarg; break;
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case 'c': count_str = optarg; break;
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case 'i': input_path = optarg; break;
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case 'I': break;
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case 'o': output_path = optarg; break;
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case 'O': break;
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case 'q': break;
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case 's': break;
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case 'S': break;
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case 'v': break;
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default: break;
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}
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}
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if (optind < argc)
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errx(1, "unexpected extra operand");
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if (input_path) {
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input_fd = open(input_path, O_RDONLY);
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if (input_fd < 0)
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err(1, "%s", input_path);
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}
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else
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input_path = "<stdin>";
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if (output_path) {
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int flags = O_WRONLY | O_CREAT | O_TRUNC;
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output_fd = open(output_path, flags, 0666);
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if (output_fd < 0)
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err(1, "%s", input_path);
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}
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else
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output_path = "<stdout>";
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struct stat input_st;
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if (fstat(input_fd, &input_st) < 0)
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err(1, "stat: %s", input_path);
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struct stat output_st;
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if (fstat(output_fd, &output_st) < 0)
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err(1, "stat: %s", output_path);
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blksize_t blksize = input_st.st_blksize < output_st.st_blksize ?
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input_st.st_blksize : output_st.st_blksize;
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if (blksize == 0)
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blksize = 512;
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size_t block_size = 0;
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if (block_size_str)
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block_size = parse_size_t(block_size_str, blksize);
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if (block_size == 0)
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block_size = blksize;
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//off_t count = -1;
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//if (count_str )
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// count = parse_off_t(count_str, blksize);
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unsigned char *block = malloc(block_size);
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if (!block)
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err(1, "malloc");
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for (off_t blocks = 0; count == -1 || blocks < count; blocks++) {
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size_t in = 0;
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while (in < block_size) {
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size_t left = block_size - in;
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ssize_t done = read(input_fd, block + in, left);
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if (done < 0)
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err(1, "%s", input_path);
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if (done == 0)
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break;
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in += done;
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}
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if ( in == 0 )
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break;
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size_t out = 0;
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while (out < in) {
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size_t left = in - out;
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ssize_t done = write(output_fd, block + out, left);
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if (done < 0)
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err(1, "%s", output_path);
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if (done == 0)
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errx(1, "%s: %s", output_path,
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"Unexpected early end of file");
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out += done;
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}
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}
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if (fsync(output_fd) < 0)
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errx(1, "sync: %s", output_path);
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// TODO: Does fsync actually sync the hardware? What does sync(1) do?
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if (close(input_fd) < 0)
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errx(1, "close: %s", input_path);
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if (close(output_fd) < 0)
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errx(1, "close: %s", output_path);
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free(block);
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return 0;
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}
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