toaruos/apps/echo.c
2018-08-15 10:07:33 +09:00

79 lines
1.6 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2013-2018 K. Lange
*
* echo - Print arguments to stdout.
*
* Prints arguments to stdout, possibly interpreting escape
* sequences in the arguments.
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
void show_usage(char * argv[]) {
printf(
"echo - print arguments\n"
"\n"
"usage: %s [-ne] ARG...\n"
"\n"
" -n \033[3mdo not output a new line at the end\033[0m\n"
" -e \033[3mprocess escape sequences\033[0m\n"
" -? \033[3mshow this help text\033[0m\n"
"\n", argv[0]);
}
int main(int argc, char ** argv) {
int use_newline = 1;
int process_escapes = 0;
int opt;
while ((opt = getopt(argc, argv, "enh?")) != -1) {
switch (opt) {
case '?':
case 'h':
show_usage(argv);
return 1;
case 'n':
use_newline = 0;
break;
case 'e':
process_escapes = 1;
break;
}
}
for (int i = optind; i < argc; ++i) {
if (process_escapes) {
for (int j = 0; j < (int)strlen(argv[i]) - 1; ++j) {
if (argv[i][j] == '\\') {
if (argv[i][j+1] == 'e') {
argv[i][j] = '\033';
for (int k = j + 1; k < (int)strlen(argv[i]); ++k) {
argv[i][k] = argv[i][k+1];
}
}
if (argv[i][j+1] == 'n') {
argv[i][j] = '\n';
for (int k = j + 1; k < (int)strlen(argv[i]); ++k) {
argv[i][k] = argv[i][k+1];
}
}
}
}
}
printf("%s",argv[i]);
if (i != argc - 1) {
printf(" ");
}
}
if (use_newline) {
printf("\n");
}
fflush(stdout);
return 0;
}