134 lines
2.1 KiB
C
134 lines
2.1 KiB
C
/*
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* The `cd' shell.
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* Just has cd and lc.
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*/
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#include <u.h>
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#include <libc.h>
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#include <bio.h>
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char *pwd;
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char *root = "/";
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void
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usage(void)
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{
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fprint(2, "usage: cdsh [-r root]\n");
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exits("usage");
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}
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int
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system(char *cmd)
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{
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int pid;
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if((pid = fork()) < 0)
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return -1;
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if(pid == 0) {
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dup(2, 1);
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execl("/bin/rc", "rc", "-c", cmd, nil);
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exits("exec");
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}
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waitpid();
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return 0;
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}
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int
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cd(char *s)
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{
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char *newpwd;
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int l;
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if(s[0] == '/') {
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cleanname(s);
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newpwd = strdup(s);
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} else {
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l = strlen(pwd)+1+strlen(s)+1+50; /* 50 = crud for unicode mistakes */
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newpwd = malloc(l);
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snprint(newpwd, l, "%s/%s", pwd, s);
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cleanname(newpwd);
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assert(newpwd[0] == '/');
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}
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if(chdir(root) < 0 || (newpwd[1] != '\0' && chdir(newpwd+1) < 0)) {
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chdir(root);
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chdir(pwd+1);
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free(newpwd);
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return -1;
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} else {
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free(pwd);
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pwd = newpwd;
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return 0;
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}
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}
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void
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main(int argc, char **argv)
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{
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char *p;
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Biobuf bin;
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char *f[2];
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int nf;
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ARGBEGIN{
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case 'r':
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root = ARGF();
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if(root == nil)
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usage();
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if(root[0] != '/') {
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fprint(2, "root must be rooted\n");
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exits("root");
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}
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break;
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default:
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usage();
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}ARGEND;
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if(argc != 0)
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usage();
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cleanname(root);
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if(cd("/") < 0) {
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fprint(2, "cannot cd %s: %r\n", root);
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exits("root");
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}
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Binit(&bin, 0, OREAD);
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while(fprint(2, "%s%% ", pwd), (p = Brdline(&bin, '\n'))) {
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p[Blinelen(&bin)-1] = '\0';
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nf = tokenize(p, f, nelem(f));
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if(nf < 1)
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continue;
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if(strcmp(f[0], "exit") == 0)
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break;
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if(strcmp(f[0], "lc") == 0) {
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if(nf == 1) {
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if(system("/bin/lc") < 0)
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fprint(2, "lc: %r\n");
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} else if(nf == 2) {
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if(strpbrk(p, "'`{}^@$#&()|\\;><"))
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fprint(2, "no shell characters allowed\n");
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else {
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p = f[1];
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*--p = ' ';
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*--p = 'c';
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*--p = 'l';
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if(system(p) < 0)
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fprint(2, "lc: %r\n");
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}
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}
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continue;
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}
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if(strcmp(f[0], "cd") == 0) {
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if(nf < 2)
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fprint(2, "usage: cd dir\n");
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else if(cd(f[1]) < 0)
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fprint(2, "cd: %r\n");
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continue;
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}
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fprint(2, "commands are cd, lc, and exit\n");
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}
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print("%s\n", pwd);
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}
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