toaruos/userspace/echo.c
Kevin Lange c88d6dcb4f Add or update the heading comments for user apps.
Adds useful descriptions to ones that were lacking them, updates ones
that were innacurate, etc.
2012-07-06 21:08:28 -07:00

68 lines
1.3 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
*
* echo
*
* Prints its arguments (with some processing, ask --help)
* to standard out.
*/
#include <stdio.h>
#include <string.h>
void usage() {
printf("echo [-n] [-e] [STRING]...\n"
" -n do not output a new line at the end\n"
" -e process escape sequences\n");
}
int main(int argc, char ** argv) {
int start = 1;
int use_newline = 1;
int process_escapes = 0;
for (int i = start; i < argc; ++i) {
if (argv[i][0] != '-') {
start = i;
break;
} else {
if (argv[i][1] == 'h') {
usage();
return 1;
} else if (argv[i][1] == 'n') {
use_newline = 0;
} else if (argv[i][1] == 'e') {
process_escapes = 1;
}
}
}
for (int i = start; i < argc; ++i) {
if (process_escapes) {
for (int j = 0; j < 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 < 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 < 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");
}
return 0;
}