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forked from bonsai/harakit

cat(1p): fix unbuffered output

This commit is contained in:
Emma Tebibyte 2023-08-07 20:38:57 -06:00
parent 9adde985d9
commit c8d6e9f5e4
Signed by untrusted user: emma
GPG Key ID: 6D661C738815E7DD
2 changed files with 94 additions and 26 deletions

View File

@ -28,9 +28,9 @@
#include <unistd.h>
int main(int argc, char *argv[]) {
int i = 1;
bool u = false;
int opt;
FILE *file;
char *usage_text = "(-u) [file...]";
int buf_size = strlen(argv[0]) + strlen("Usage: ") + strlen(usage_text) + 3;
char *usage = calloc(buf_size, buf_size);
@ -39,8 +39,7 @@ int main(int argc, char *argv[]) {
snprintf(usage, buf_size, "Usage: %s (-u) [file...]\n", argv[0])
) < 0 ) {}
int opt;
extern int optind;
while ((opt = getopt(argc, argv, "u")) != -1) {
switch(opt) {
/*
@ -50,17 +49,17 @@ int main(int argc, char *argv[]) {
* without delay as each is read.
*/
case 'u':
i = 2;
u = true;
break;
default:
break;
}
}
argv += optind;
argc -= optind;
FILE *file;
for (; i <= (argc - 1); i++) {
for (int i = 0; i < argc; i++) {
int byte = 0;
/*
* From cat(1p):
*
@ -72,33 +71,24 @@ int main(int argc, char *argv[]) {
* but shall accept multiple occurrences of '-' as a file
* operand.
*/
printf("argv[%d]: %s\n", i, argv[i]);
if (argv[i] == "-" || u && (argc - 1) == 1 || !u && argc == 1) {
file = fdopen(0, "r");
if (argv[i] == "-" || argc == 0) {
file = stdin;
} else if ((file = fopen(argv[i], "r")) == NULL) {
// TODO: Add error handling
fputs(usage, stderr);
return EX_NOINPUT;
}
int byte = 0;
for (char *buf = calloc(4096, 1); byte != EOF; fputs(buf, stdout)) {
byte = fgetc(file);
if (u) {
while (byte != EOF) {
byte = fgetc(file);
putchar(byte);
}
} else {
char *buf = calloc(1, 4096);
while (byte != EOF) {
byte = fgetc(file);
fputc(byte, fdopen(1, "r"));
snprintf(buf, 4096, "%c", byte);
}
}
if (fclose(file) == -1) {
fprintf(stderr, "%s: %s: Error closing file.\n", argv[0], argv[i]);
return EX_OSERR;
}
if (file != stdin) { fclose(file); }
}
return EX_OK;

78
trincat.c Normal file
View File

@ -0,0 +1,78 @@
#include <errno.h> /* maybe */
#include <fcntl.h> /* no */
#include <sysexits.h> /* sure */
#include <stdbool.h> /* no */
#include <stdio.h> /* yes */
#include <stdlib.h> /* yes */
#include <string.h> /* maybe */
#include <unistd.h> /* yes */
#define BUF_SIZE 4096
unsigned char u = 0; /* unbuffered */
unsigned char buf[BUF_SIZE];
void usage(char *argv0){
fprintf(stderr, "Usage: %s (-u) (file...)\n", argv0);
exit(EX_USAGE);
}
int main(int argc, char *argv[]) {
char *argv0;
extern int optind;
int c;
FILE *in;
argv0 = argv[0];
while ((c = getopt(argc, argv, "u")) != -1) {
switch(c) {
/*
* From cat(1p):
*
* -u Write bytes from the input file to the standard output
* without delay as each is read.
*/
case 'u':
u = 1;
break;
default:
usage(argv[0]);
}
}
while(++argv != NULL) /* increments over argv[0] */
/*
* From cat(1p):
*
* file A pathname of an input file. If no file operands are
* specified, the standard input shall be used. If a file is
* '-', the cat utility shall read from the standard input at
* that point in the sequence. The cat utility shall not close
* and reopen standard input when it is referenced in this way,
* but shall accept multiple occurrences of '-' as a file
* operand.
*/
if(argv[0][0] == '-' && argv[0][1] == '\0') in = stdin;
else if ((in = fopen(argv[0], "r")) == NULL) {
// TODO: Add error handling
usage(argv0);
return EX_NOINPUT;
}
int byte = 0;
char *buf = calloc(4096, 1);
while ((c = fgetc(in) != EOF)) {
if (u) {
putchar(c);
} else {
/* fucky wucky buffering */
}
}
if(!u) fputs(buf, stdout);
if(in != stdin) fclose(file); /* who cares if it cant close */
}
return EX_OK;
}