1 files changed, 121 insertions, 0 deletions
diff --git a/src/execline/shift.c b/src/execline/shift.c
new file mode 100644
index 0000000..b09ba38
--- /dev/null
+++ b/src/execline/shift.c
@@ -0,0 +1,121 @@
+/* ISC license. */
+
+#include <skalibs/sgetopt.h>
+#include <skalibs/uint.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/djbunix.h>
+#include <execline/execline.h>
+
+#define USAGE "shift [ -n arg# ] [ -b block# ] prog..."
+#define dieusage() strerr_dieusage(100, USAGE)
+
+int main (int argc, char const *const *argv, char const *const *envp)
+{
+  unsigned int strict = el_getstrict() ;
+  unsigned int b = 0 ;
+  unsigned int n = 0 ;
+  unsigned int sharp ;
+  unsigned int i = 0 ;
+  PROG = "shift" ;
+  {
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      register int opt = subgetopt_r(argc, argv, "n:b:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'n' :
+          if (!uint0_scan(l.arg, &n)) dieusage() ;
+          i = 1 ;
+          break ;
+        case 'b' :
+          if (!uint0_scan(l.arg, &b)) dieusage() ;
+          i = 1 ;
+          break ;
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
+  }
+  if (!argc) dieusage() ;
+  if (i) i = 0 ; else n = 1 ;
+  {
+    char const *x = env_get2(envp, "#") ;
+    if (!x) strerr_dienotset(100, "#") ;
+    if (!uint0_scan(x, &sharp)) strerr_dieinvalid(100, "#") ;
+  }
+
+
+ /* Shift n args */
+
+  if (n > sharp)
+  {
+    if (strict)
+    {
+      char fmtn[UINT_FMT] ;
+      char fmtsharp[UINT_FMT] ;
+      fmtn[uint_fmt(fmtn, n)] = 0 ;
+      fmtsharp[uint_fmt(fmtsharp, sharp)] = 0 ;
+      if (strict == 1)
+        strerr_warnwu5x("shift", " ", fmtn, " arguments: got ", fmtsharp) ;
+      else
+        strerr_diefu5x(100, "shift", " ", fmtn, " arguments: got ", fmtsharp) ;
+    }
+    n = sharp ;
+  }
+
+
+ /* Shift b blocks */
+
+  for (; i < b ; i++)
+  {
+    for (;;)
+    {
+      char const *x ;
+      unsigned int base = n ;
+      char fmt[UINT_FMT] ;
+      fmt[uint_fmt(fmt, ++n)] = 0 ;
+      if (n > sharp)
+      {
+        char fmti[UINT_FMT] ;
+        fmti[uint_fmt(fmt, i)] = 0 ;
+        strerr_diefu6x(100, "shift", " block ", fmti, ": too few arguments (", fmt, ")") ;
+      }
+      x = env_get2(envp, fmt) ;
+      if (!x) strerr_dienotset(100, fmt) ;
+      if ((x[0] == EXECLINE_BLOCK_END_CHAR) && (!EXECLINE_BLOCK_END_CHAR || !x[1])) break ;
+      if ((x[0] != EXECLINE_BLOCK_QUOTE_CHAR) && strict)
+      {
+        char fmti[UINT_FMT] ;
+        char fmtp[UINT_FMT] ;
+        fmti[uint_fmt(fmti, i)] = 0 ;
+        fmtp[uint_fmt(fmtp, n - base)] = 0 ;
+        if (strict == 1)
+          strerr_warnw6x("unquoted positional ", x, " at block ", fmti, " position ", fmtp) ;
+        else
+          strerr_dief6x(100, "unquoted positional ", x, " at block ", fmti, " position ", fmtp) ;
+      }
+    }
+  }
+
+
+ /* n = shift value; modify the env */
+
+  {
+    register unsigned int i = 1 ;
+    char fmt[UINT_FMT] ;
+    fmt[uint_fmt(fmt, sharp - n)] = 0 ;
+    if (!pathexec_env("#", fmt)) strerr_diefu1sys(111, "pathexec_env") ;
+    for (; i <= sharp ; i++)
+    {
+      char fmu[UINT_FMT] ;
+      fmt[uint_fmt(fmt, i)] = 0 ;
+      fmu[uint_fmt(fmu, i + n)] = 0 ;
+      if (!pathexec_env(fmt, i <= (sharp - n) ? env_get2(envp, fmu) : 0))
+        strerr_diefu1sys(111, "pathexec_env") ;
+    }
+  }
+  pathexec(argv) ;
+  strerr_dieexec(111, argv[0]) ;
+}