27 lines
491 B
C
27 lines
491 B
C
#include <errno.h>
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#include <stdio.h>
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#include <unistd.h>
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int usage(char *argv0) {
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printf("Usage: %s\n", argv0);
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return 1;
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}
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int main(int argc, char *argv[]){
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int opt;
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while ((opt = getopt(argc, argv, ":")) != -1) {
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switch (opt) {
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case '?':
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fprintf(stderr, "%s: invalid option -- '%c'\n", argv[0], optopt);
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return usage(argv[0]);
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}
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}
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if (getlogin() != NULL) {
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printf("%s\n", getlogin());
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} else {
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perror(argv[0]);
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}
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return errno;
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}
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