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author | Mole Shang <[email protected]> | 2024-02-11 14:44:22 +0800 |
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committer | Mole Shang <[email protected]> | 2024-02-11 16:06:15 +0800 |
commit | 2fe04bc8faa4bf737a86c36a8017473e84814f3b (patch) | |
tree | 2146d3dae86f21060e2e807ad364f5a949fd1c53 /user/xargs.c | |
parent | 5ce1f630132d8b7b35b9dc46b4a55f860eb85d5c (diff) | |
parent | 48a5e34fcd07852b4a68825ce8e37feb6f6d04d7 (diff) | |
download | xv6-labs-2fe04bc8faa4bf737a86c36a8017473e84814f3b.tar.gz xv6-labs-2fe04bc8faa4bf737a86c36a8017473e84814f3b.tar.bz2 xv6-labs-2fe04bc8faa4bf737a86c36a8017473e84814f3b.zip |
Merge branch 'traps' into cow
Conflicts:
.gitignore
Makefile
conf/lab.mk
Diffstat (limited to 'user/xargs.c')
-rw-r--r-- | user/xargs.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/user/xargs.c b/user/xargs.c new file mode 100644 index 0000000..b5b9bee --- /dev/null +++ b/user/xargs.c @@ -0,0 +1,60 @@ +#include "kernel/types.h" + +#include "kernel/param.h" +#include "kernel/stat.h" +#include "user/user.h" + +#define is_blank(chr) (chr == ' ' || chr == '\t') + +int +main(int argc, char* argv[]) +{ + char buf[2048], ch; + char* p = buf; + char* v[MAXARG]; + int c; + int blanks = 0; + int offset = 0; + + if (argc <= 1) { + fprintf(2, "usage: xargs <command> [argv...]\n"); + exit(1); + } + + for (c = 1; c < argc; c++) { + v[c - 1] = argv[c]; + } + --c; + + while (read(0, &ch, 1) > 0) { + if (is_blank(ch)) { + blanks++; + continue; + } + + if (blanks) { + buf[offset++] = 0; + + v[c++] = p; + p = buf + offset; + + blanks = 0; + } + + if (ch != '\n') { + buf[offset++] = ch; + } else { + v[c++] = p; + p = buf + offset; + + if (!fork()) { + exit(exec(v[0], v)); + } + wait(0); + + c = argc - 1; + } + } + + exit(0); +} |