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src/psops/pspipe.c
2023-11-18 11:56:42 -07:00

54 lines
1.1 KiB
C

#include <errno.h> /* errno */
#include <stdio.h> /* fprintf(3), stderr, "psops.c" */
#include <string.h> /* strerror(3) */
#include <sysexits.h> /* EX_OSERR */
#include <unistd.h> /* execvp(3) */
#include <sys/types.h> /* <sys/wait.h> */
#include <sys/wait.h> /* wait(2) */
#include "libpsargs.h" /* corresponding_arg(3), "psops.c" */
static char *program_name = "pspipe";
/* At the start of the loop argv[0] is { '[', '\0' } and file descriptor 0 is
* the intended standard input */
int
f(char **argv){
static int child;
char **corr;
int fd[2];
int r;
*(corr = corresponding_arg(argv)) = NULL;
if(corr[1] != NULL){
if(pipe(fd) != 0){
fprintf(stderr,
"%s: %s: %s\n",
program_name, argv[1], strerror(errno)
);
return EX_OSERR;
}
if((r = fork()) == -1){
fprintf(stderr, "%s: %s\n",
program_name, strerror(errno)
);
return EX_OSERR;
}
if(r == 0)
dup2(fd[0], 0);
else
dup2(fd[1], 1);
close(fd[1]);
close(fd[0]);
if(r == 1)
execvp(argv[1], argv+1);
}
argv = corr;
return *++argv == NULL
? WEXITSTATUS(child)
: f(corr + 1);
}
#include "psops.c"