Luna/apps/src/cat.c

45 lines
1.0 KiB
C

#define _GNU_SOURCE // for program_invocation_name
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void cat(FILE* stream)
{
char buf[BUFSIZ];
do {
fgets(buf, BUFSIZ, stream);
if (ferror(stream))
{
perror(program_invocation_name);
exit(EXIT_FAILURE);
}
fputs(buf, stdout);
} while (!feof(stream));
}
int main(int argc, char** argv)
{
if (argc == 1) cat(stdin);
else
{
for (int i = 1; i < argc; i++)
{
if (strcmp(argv[i], "-") == 0) cat(stdin);
else if (strcmp(argv[i], "-n") == 0 || strcmp(argv[i], "--newline") == 0)
putchar('\n');
else
{
FILE* stream = fopen(argv[i], "r");
if (!stream)
{
perror(program_invocation_name);
return EXIT_FAILURE;
}
cat(stream);
fclose(stream);
}
}
}
}