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cat(1p): refactor to get no args working

This commit is contained in:
Emma Tebibyte 2023-08-13 23:30:03 -06:00
parent da2ebdb1e1
commit b57a7179a5
Signed by untrusted user: emma
GPG Key ID: 6D661C738815E7DD
1 changed files with 48 additions and 39 deletions

View File

@ -27,9 +27,37 @@
#include <string.h>
#include <unistd.h>
void cat(FILE *file, bool u) {
int byte = 0; /* variable for storing bytes as they are read */
int p = 0; /* index counter for bytes in buffered reading */
char buf[4096]; /* buffer for buffered reading */
while (byte != EOF) {
byte = fgetc(file);
if (u) {
putchar(byte);
} else {
if (p > sizeof(buf)) {
fputs(buf, stdout);
p = 0;
}
buf[p] = byte;
p += 1;
}
}
fwrite(buf, 1, p, stdout);
fflush(stdout);
if (file != stdin) { fclose(file); }
}
int main(int argc, char *argv[]) {
bool u = false;
int opt;
int i;
extern int optind;
while ((opt = getopt(argc, argv, "u")) != -1) {
@ -49,22 +77,27 @@ int main(int argc, char *argv[]) {
}
}
int i = 1;
FILE *file;
/*
* 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 (optind == argc) {
cat(stdin, u);
}
FILE *file;
for (i = optind; i < argc; i++) {
/*
* 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[i] == "-" || argc == 1) {
if (argv[i][0] == '-' && argv[i][1] != '\0') {
continue;
} if (strcmp(argv[i], "-") == 0) {
file = stdin;
} else if ((file = fopen(argv[i], "r")) == NULL) {
switch (errno) {
@ -88,31 +121,7 @@ int main(int argc, char *argv[]) {
return EX_UNAVAILABLE;
}
}
int byte = 0; /* variable for storing bytes as they are read */
int p = 0; /* index counter for bytes in buffered reading */
char buf[4096]; /* buffer for buffered reading */
while (byte != EOF) {
byte = fgetc(file);
if (u) {
putchar(byte);
} else {
if (p > sizeof(buf)) {
fputs(buf, stdout);
p = 0;
}
buf[p] = byte;
p += 1;
}
}
fwrite(buf, 1, p, stdout);
fflush(stdout);
if (file != stdin) { fclose(file); }
cat(file, u);
}
return EX_OK;