35 lines
1.0 KiB
C
35 lines
1.0 KiB
C
#include <unistd.h>
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#include <stdio.h>
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#define MAX_BUF_SIZE (1 * 1024 * 1024)
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#define MIN(x, y) ((x) <= (y) ? (x) : (y))
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// This program consumes a specific amount of data from stdin
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int main(int argc, const char *argv[]) {
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// Get the total number of bytes to read
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size_t remain_bytes = 0;
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while (read(0, &remain_bytes, sizeof(remain_bytes)) != sizeof(remain_bytes));
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// Get the size of buffer to use
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size_t buf_size = 0;
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while (read(0, &buf_size, sizeof(buf_size)) != sizeof(buf_size));
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if (buf_size > MAX_BUF_SIZE) {
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printf("ERROR: the required buffer size (%lu) is tool large\n", buf_size);
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return -1;
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}
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// Read a specified amount of data in a buffer of specified size
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char buf[MAX_BUF_SIZE];
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while (remain_bytes > 0) {
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size_t len = MIN(buf_size, remain_bytes);
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if ((len = read(0, &buf, len)) < 0) {
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printf("ERROR: failed to write to pipe\n");
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return -1;
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}
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remain_bytes -= len;
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}
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return 0;
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}
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