Use knitr's output hook to hide path

knitr-hook.md

library(sf)

## Linking to GEOS 3.6.1, GDAL 2.2.3, proj.4 4.9.3

nc <- st_read(system.file("shape/nc.shp", package="sf"))

## Reading layer `nc' from data source `C:\path\to\R\win-library\3.5\sf\shape\nc.shp' using driver `ESRI Shapefile'
## Simple feature collection with 100 features and 14 fields
## geometry type:  MULTIPOLYGON
## dimension:      XY
## bbox:           xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
## epsg (SRID):    4267
## proj4string:    +proj=longlat +datum=NAD27 +no_defs

knitr-hook.Rmd

---
output: github_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)

orig_hook <- knitr::knit_hooks$get("output")

knitr::knit_hooks$set(
  output = function(x, options) {
    x <- orig_hook(x, options)
    ptn <- normalizePath(Sys.getenv("HOME"))
    gsub(ptn, "C:\\path\\to", x, fixed = TRUE)
  }
)
```

```{r}
library(sf)

nc <- st_read(system.file("shape/nc.shp", package="sf"))
```